Smartphone and tablet processor market share in 2014

Strategy Analytics has published its yearly report detailing global smartphone application processor market share in 2014. The total market had sales of about $21 billion with robust growth of 21%. The report shows that Qualcomm continued to lead the market in terms of revenue share with 52%, followed by Apple with 18% and MediaTek with 14%. The Apple number most likely reflects an estimate because Apple does not sell its chips to third parties. In fourth and fifth place were Speadtrum and Samsung LSI. The report mentions that HiSilicon, Intel and MediaTek had bigger growth than Qualcomm in 2014.

Qualcomm's strength based on Snapdragon 800 series wins in higher-tier phones

According to the report, Qualcomm's leadership was largely based on design wins for its Snapdragon 801 and Snapdragon 805 SoCs in the higher-tier market. Examples of this include the Samsung Galaxy S5 and LG G3. However, as I have previously reported Samsung has increased its use of in-house application processors starting from the second half of 2014, culminating in the exclusive use of Exynos 7420 in the Galaxy S6 in 2015, putting pressure on Qualcomm.

Baseband share in 2014

Strategy Analytics has also published a report with details about baseband (modem) market share in smartphones. According to the report, LTE (4G) basebands accounted for 50% of cellular baseband share in 2014, and the figure is likely to increase significantly in 2015. Qualcomm led in LTE basebands, but HiSilicon, Intel, Marvell, MediaTek and Samsung also increased LTE baseband shipments.

In terms of revenues in the overall baseband market, Qualcomm, MediaTek, Speadtrum, Marvell and Intel had the top positions in 2104. Qualcomm had 66% revenue share, followed by MediaTek with 17% and Speadtrum with 5% sare. Given the product lines of the respective companies in 2014, Qualcomm's revenues are based on both integrated SoC and separate modems, while Intel's sales were mostly separate modem chips, while the other players mostly shipped a mix of integrated SoCs and modem chips.

Comparison with 2013

Comparing with the reports that Strategy Analytics issued for 2013, Qualcomm saws it baseband revenue share remain relatively stable at 66% compared to 64% in 2013. MediaTek saw its AP market share increase from 10% in 2013 to 14% in 2014, and its baseband share increased.

Tablet processor market in 2014

According to another report issued by Strategy Analytics, the market for tablet processors grew 18% in 2014 to $4.2 billion. The top-five revenue share positions were occupied by Apple, Intel, Qualcomm, MediaTek and Samsung LSI. Apple led with 27% share (which must be an estimate), followed by Intel with 17% and Qualcomm with 16% share.

Notable is the absence among the top five of traditional leaders in the Chinese white-box market such as Rockchip and Allwinner. This most likely reflects in increase in brand name tablet shipments at the expense of the white-box tablet market, the low selling prices of white-box tablet processor and the encroachment of MediaTek and Intel into that segment.

Source: Strategy Analytics (Smartphone AP market share), Strategy Analytics (cellular baseband market share), Strategy Analytics (Tablet processor market share)

TSMC's 16 nm FinFET sees adoption by Qualcomm and Apple, competes with Samsung

TSMC will receive majority of Apple A9 business

According to reports, TSMC will receive the majority of Apple A9 SoC orders, which includes the A9 for next-generation iPhones and A9X for iPads. According to sources quoted by EE Times, Apple had originally planned to give Samsung a majority of the Apple A9 orders, but has recently shifted orders to TSMC, most likely using a 16 nm FinFET process.

Because ramping up production of a similar chip from a second source with different foundry technology is challenging and complicated, I believe it is likely that A9 production will be overwhelmingly (and perhaps exclusively) concentrated at TSMC. A parallel can be drawn with various reports from last year, which for a long time continued to echo incorrect projections that Samsung would serve a significant portion of the production of Apple's A8 generation SoCs, which has not turned out not to be the case.

In the mean time, TSMC's revenues continue to be a relatively high level despite Q1usually being seasonally down, with strong demand for 20 nm production, most likely reflecting continuing demand from Apple, which is offsetting weakness from Qualcomm for leading-edge processes. There have been rumours about an upcoming iPhone 6S and a lower cost iPhone 6C model which may involve substantial unit volumes. Apple's iPhone unit shipments have also been boosted by strong demand in China.

Low yield at Samsung and Exynos ramp contribute to TSMC orders

According to a source quoting sources in South Korea, TSMC's yield rate for its 16 nm FinFET process is better than that of Samsung's 14 nm process. Moreover, Samsung is seeing strong upcoming demand for it flagship Galaxy S6 smartphone, which uses the Exynos 7420 SoC produced on its 14 nm FinFET process, and most likely needs all capacity it can get to ramp up production of this SoC. Samsung also increasingly uses Exynos 7420 and other internally-developed SoCs for other product lines, such as other smartphone models as well as tablets.

Qualcomm said to have limited-time exclusive use of TSMC's 16FF+ technology

According a report by EETimes from a semiconductor industry conference in January, Qualcomm is likely to have locked up exclusive use of TSMC's 16FF+ process technology for about six months. The article appears to quote sources affiliated with Qualcomm that state that Qualcomm feels competitors such as MediaTek took advantage of previous-generation process technology (28HPM) that Qualcomm helped develop at TSMC, without having made the development investment that Qualcomm made.

However, this policy would be contrary to the principles based on which TSMC has operated for a long time, although the initial ramp of 20 nm at TSMC last year also seemed to be locked-up by another company (Apple). Its seems corporate pressure from these giant companies, backed by billions of dollars of cash, is forcing TSMC into these kinds of commitments.

The article mentions that the later access to 16FF+ won't affect MediaTek's mainstream products serving the mid-range to entry-level segments, because 28 nm technologies will continue to be used for such products in the market.

Leaked power consumption graphs suggest increased power efficiency

Power consumption graphs of current and upcoming high-end Qualcomm SoCs running a 3D game at high detail settings suggest power consumption and heat production of Qualcomm's unannounced Snapdragon 815 processor will be considerably lower than that of the Snapdragon 801 and Snapdragon 810, with Snapdragon 810 showing particularly unfavourable characteristics, as confirmed by widespread reports and reviews of Snapdragon 810-based devices.

Snapdragon 815 is unannounced and few details are known about it, with some reports suggesting the use of a next-generation Krait CPU core. Use of ARM Cortex-A72 processor cores appears to be not unlikely, since this core seems to be close to actual production. Most likely, the decreased heat production, which is likely to be associated with lower power consumption, is made possible by the use of the next-generation 16 nm FinFET process at TSMC.

Similar improvements in power consumption were observed for Snapdragon 620, which uses Cortex-A72 cores, when compared to the mid-range Snapdragon 615 SoC, which is reported to also have heating issues. Snapdragon 620, which has been announced, is also likely to have significantly higher CPU performance than Snapdragon 615 due to the use of Cortex-A72 cores, versus Cortex-A53 for Snapdragon 615, while also likely being produced on a much more efficient process (possibly  TSMC's 16FF+), since Snapdragon 615 is manufactured on a low-efficiency 28LP process.

Sources: EE Times (ISS 2015 conference report), EE Times (Apple A9 orders article), STJS Gadgets Portal (Snapdragon heat production graphs)

Updated 25 March 2015 (Add comments about 20 nm Apple production at TSMC).

Qualcomm and MediaTek see challenges in smartphone SoC market

Both Qualcomm and MediaTek recently reported financial results for the fourth quarter of Q4 2014 and made projections for future periods. Both companies are seeing challenges that are already affecting their revenues and market share now or later in 2015.

Qualcomm lowers forecast for 2015 due to weakness at major customer

In their financial report for Q4 2014, Qualcomm lowered their outlook for 2015, citing as one of the reasons reduced demand from a major customer as that customer has not selected the Snapdragon 810 processor for an upcoming flagship product. This is widely believed to refer to Samsung's upcoming Galaxy S6. In fact the trend of increasing use of in-house Exynos processors already started last year, as models such as Galaxy Alpha, Galaxy S5 Mini and Galaxy Note 4 already saw increasing use of Samsung's own Exynos processors, including modem technology in some cases.

Qualcomm also mentions a share shift among major OEMs that will result in relatively more modem chips as opposed to SoCs (clearly referring to Apple, which only uses Qualcom's modem chips), as well as heightened competition in China. Recently, Qualcomm also recently announced a resolution of the anti-trust investigation by authorities in China, which amounts to a reduction in the patent royalty rate it charges to customers in China.

Qualcomm's total market share currently still strong

At the moment, Qualcomm's market share for smartphone SoCs is still strong as shown by unit shipments and revenues for Q4 2014 and Qualcomm's estimates for Q1 2015, although its product mix has shifted to lower-end products. In comparison to competitor MediaTek, Qualcomm is doing much better in terms of maintaining or growing unit shipments (with Qualcomm in fact seeing a 14% increase in unit shipments in Q4 2014), suggesting that Qualcomm is taking market share from MediaTek as products such as Snapdragon 410 and the new Snapdragon 210 take over large parts of the low-end cost-sensitive market (especially in China) where MediaTek's 3G solutions where previously dominant.

MediaTek losing market share despite successful new products

Meanwhile, although MediaTek has seen widespread adoption of its new MT6752 and MT6732 SoCs with integrated LTE modem for the cost-sensitive mid-range market, the company saw lower unit shipments in Q4 2014 and predicts a 10 to 18% revenue decline for Q1 2015, suggesting its smartphone SoC shipments are under pressure. Given the fact that the new 4G chips have higher selling prices than existing 3G chips, the revenue decline probably reflects a relatively dramatic decline in shipments of existing 3G solutions, with resulting loss of total market share, although price reductions may also play a role. MediaTek has been affected especially by the late introduction of integrated 4G solutions and the lack of a low-end 4G solution and to a lesser extend the delayed introduction of the high-end MT6795.

Captive mobile SoC use becoming more important

Within the total smartphone SoC market (and also in the tablet maket), captive supply (whereby a smartphone manufacturer uses its own SoCs in its smartphone models) is becoming more important, which affects the market opportunity for companies such as Qualcomm and MediaTek. I already mentioned Samsung's increasing use of Exynos processors, which has a significant impact as Samsung is one of the two largest smartphone manufacturers. A major Chinese manufacturr, Huawei, is also increasingly using SoCs from its own HiSilicon division, also extending to lower end models. Apple's gains in market share also has an effect (especially on the high-end market) since it uses proprietary SoCs.

In the tablet market, the low-end and Chinese white-box market is seeing a sharp reduction in shipments in Q1 2015, with market share shifting to brand names (where captive solutions are more important, such as at Samsung) as total shipments are estimated to decline dramatically. This greatly affects traditional players in the tablet SoC market such as Rockchip, Allwinner and MediaTek. Intel's strategy of subsidizing tablet SoCs has also had an impact. According to DigiTimes, the total tablet market will decline 30% sequentially in Q1 2015, with estimates of a decline of 12% for the whole year 2015.


Sources: DigiTimes (tablet market article), DigiTimes (MediaTek results), Qualcomm, MediaTek

No more wafer capacity shortage at TSMC?

For November 2014, TSMC somewhat unexpectedly reported a revenue decline to US$2.31 billion, 10% lower than the historical high achieved in October 2014, reversing several months of continually increasing monthly revenues at TSMC amid a shortage of capacity for clients of TSMC and continuous investments into capacity expansion.

An article in the Taipei Times from 14 December 2014 further reports on TSMC's sales in Q4 2014 and its future prospects, with a senior TSMC official saying that the decline was not a suprise, as "cautious inventory adjustment actions taken by some of our customers will bring slower fourth-quarter demand". There have been reports that some clients may have double-ordered chips in the face of the capacity shortage that existed previously. TSMC's sales in Q4 2014 will still be a quarterly record based on strong demand for 4G smartphones in China and increased demand for TSMC's advanced 20nm process technology.

TSMC's Q4 2014 revenues are still projected to be near NT$220 million (about US$7.0 billion), a sequential increase of about 5% from the previous quarter, which would complete a strong 27% increase in revenues for the whole year 2014 over the previous year, extending TSMC's leadership of the foundry industry.

TSMC's revenues for 2015 are forecast to further increase by 15 to 20%, based on strong demand for 20nm chips, new chips manufactured using its 16nm FinFET process technology and continuing demand for 28nm chips, as well as demand for trailing-edge 8" wafer capacity.

Apple ramp has peaked, Android chip vendors cautious

As mentioned in the recent articles, a likely major reason for the revenue decline in November and for Q4 2014 is that Apple's production of the Apple A8 and Apple A8X processors already peaked in October in order to achieve sufficient production in time for the 2014 holiday season. Additionally, demand from Android device vendors (such as Qualcomm and MediaTek) has not picked up, so that another sales decline for December 2014 is expected.

The decline in demand appears to be concentrated in the 20nm and 28nm HPM (High-Performance Mobile) process technologies, which were earlier in extremely short supply, and are used by Apple for its A8 SoCs at 20nm, and primarily at 28nm by Qualcomm for its high-end SoCs such as the Snapdragon 800 series and by MediaTek for various mid-range chips (such as MT6592, MT6595 and MT8135V), as well as its new 64-bit SoCs (MT6732, MT6752 and MT6795) that are currently ramping.

Decreased use of TSMC-produced chips by Samsung

An important contributor to the decline in demand for mobile processor capacity at TSMC is likely to be a decline in the utilization of TSMC-produced smartphone SoCs at Samsung. Samsung has recently been facing an overall sales decrease for its smartphone business, although Q4 2014 has been projected to see a recovery. However, Samsung is aggressively increasing the use of its own Exynos series SoCs in its smartphones, especially high-end models, after reduced orders from Apple left Samsung's advanced logic fabs underutilized.

Chips like the Exynos 7 Octa perform adequately for a high-end device and have significantly decreased Samsung's reliance on Qualcomm, which manufactures at TSMC. While Qualcomm is likely to continue to sell a large number of low-cost chips such as Snapdragon 410 to Samsung, the overall product mix from Qualcomm into Samsung has likely shifted to lower-end chips that have a significantly smaller die size, and thus require significantly less wafer capacity for a given amount of chips.

Transition to smaller die size for Qualcomm's mid-range performance-oriented SoCs

For some time, Qualcomm has had a gap in its product line, with Snapdragon 400 being used for the low-end as well as part of the mid-range segment, and a large performance and cost gap to the high-end Snapdragon 800 series, while Snapdragon 600 (without integrated baseband) was out of the picture. This resulted in a relatively large amount of high-end, large die-size Snapdagon 800 series chips being used in smartphones, even for models that do not quite require that level of performance.

However, Qualcomm has introduced new SoCs such as Snapdragon 615, an octa-core Cortex-A53-based SoC with a mid-range GPU, which can address the perfomance requirements of a significant part of the performance-oriented segment at a much lower cost, importantly while consuming significantly less wafer capacity at TSMC due the smaller die size of the SoC. This product transition at Qualcomm likely contributes to lower wafer requirements for Qualcomm at TSMC as production of smaller chips like Snapdragon 210, Snapdragon 410 and Snapdragon 615 increases at the expense of Snapdragon 801/805, and as a result contributes to TSMC's revenue decline.

Product transition at MediaTek

Meanwhile, MediaTek is also in a product transition from its 3G product line to its new product line with integrated 4G baseband. Because it has been late with integrated 4G, MediaTek has come under some pressure in China, with more of its sales being concentrated at the low of the market with SoCs such as dual-core chips for worldwide export markets, which take a smaller amount of wafer capacity.

MediaTek's new mid-range performance-oriented chips such as MT6752 and MT6795 are competitive, and have the potential to reduce overall market die size requirements and improve device cost and efficiency for the performance-oriented segment. However, they, as well as the lower-end MT6732, do not address the highest-volume low-end 4G segment, which in the near term is more likely to be addressed by Qualcomm with its Snapdagon 410 and upcoming Snapdragon 210 series, the latter of which implies with further reductions in wafer requirements due to smaller die size.

Other smartphone SoC clients at TSMC

HiSilicon has been producing increasing numbers of smartphone SoCs at TSMC for use in Huawei smartphones, but may have been affected by inventory issues, and there's also evidence of HiSilicon transitioning to more cost-effective designs such as the octa-core Cortex-A53-based Kirin 620, partly displacing its existing big.LITTLE Cortex-A15/Cortex-A7-based Kirin 920/925 series, which have a relatively large die size.

Other TSMC clients for leading-edge processes

Other companies that do not concentrate on smartphones such as Broadcom (embedded communications/networking) and NVIDIA (primarily PC-class GPUs, as well as high-end tablet SoCs) may welcome the increased capacity as it gives them increased production flexibility amid strong demand for their chips.

Not good for foundry competitors

Foundry competitors such as GlobalFoundries, which are already struggling, are not likely to benefit from the alleviation of capacity constraints at TSMC, because potential clients may now be less determined into moving part of their production from TSMC to alternative suppliers such as GlobalFoundries (as well as Samsung and UMC). Moving products to new foundries involves considerable investment and time since their processes are different from TSMC's processes, and as long as TSMC has enough capacity there is little reason for clients to not concentrate production at TSMC with its industry-leading performance.

Sources: DigiTimes (TSMC November revenues) , Taipei Times (TSMC article)

Updated December 26, 2014.

Analysis of GPU performance of mobile SoCs based on GFXBench results

In this post, I am analysing the GPU performance of different GPUs and SoCs based on the results database of GFXBench, one of the leading mobile GPU benchmarks. Apart from providing a GPU performance comparison for different SoCs, GFXBench results provide sufficient detail to get an impression of metrics like fill rate, triangle rate and shader performance, allowing one to draw conclusions about what the bottleneck is in a particular implementation.

GFXBench results table for mobile SoCs

The folowing table show detailed GFXBench 3.0 results for a large number of mobile SoC platforms and devices. The results are grouped by smartphone and tablet devices, and further grouped for similar chips (smartphone table) or in alphabetical order by chip (tablet table).

For a high-resolution version, view/copy/save the image above using the browser.

The same table is shown below, but sorted on the T-Rex Offscreen benchmark score in descending order, which provides a reasonable device-independent indication of GPU performance.

For a high-resolution version, view/copy/save the image above using the browser.

Top-performing SoCs: Apple A8/A8X, Snapdragon 805, NVIDIA Tegra K1 and Exynos 7 Octa

Apple's A8 and A8X SoCs, NVIDIA's Tegra K1 (both the Cortex-A15/A7-based version as well as the NVIDIA Denver-based version) as well as Qualcomm's Snapdragon 805 lead the pack for mobile GPU performance. What most of these chips have in common is a large number of GPU pixel processing cores and a wide DRAM interface (especially in the case of the Apple A8X and Snapdragon 805) to achieve high memory bandwidth. The Apple A8X has been reported by AnandTech to contain an eight cluster PowerVR Series 6 GPU, twice the number of clusters of the GPU inside the Apple A8.

In the OpenGL ES 2.0-based T-Rex offscreen benchmark, the Apple A8X as used in the iPad Air 2 leads, closely followed by the respective versions of Tegra K1 in the HTC Nexus 9 and the NVIDIA Shield Tablet. The Apple A8 and Snapdragon 805 show significantly slower but comparable performance in the T-Rex offscreen benchmark (although still very fast for most purposes), although Snapdragon 805 shows significantly higher low-level metrics such as fillrate, alpha blending bandwidth and shader processing throughput. Snapdragon 805 (with Adreno 420 GPU) has an effective 128-bit memory interface (similar to Apple A8X), which suggests the Apple A8 (with 64-bit memory interface) has greater efficiency within the limitations of the lower memory bandwidth, probably helped by the use of large on-chip caches (including the L3 cache). Samsung's Exynos 7 Octa (Exynos 5433, with Mali-T760 MP6) is somewhat slower than Apple A8 and Snapdragon 805, and so is the slowest of the high-performance processors in terms of GPU power (while being near the lead in terms of CPU performance).

In the OpenGL ES 3.0-based Manhattan benchmark (offscreen, so that the results are largely independent of screen resolution), the Apple A8X and NVIDIA Tegra K1 provide comparable performance (a score just above 2000), while the Snapdragon 805 follows at a considerable distance with a score of about 1200, similar to the score achieved by the Apple A8 inside the iPhone 6 and iPhone 6 Plus. Samsung's Mali-T760 MP6-based Exynos 7 Octa (as represented by the Exynos-based version of the Galaxy Note 4) follows with a score of about 1100.

High-end: Snapdragon 801, Exynos 5 Octa, Apple A7

Qualcomm's Snapdragon 801 with Adreno 330 GPU has been widely used in performance-oriented devices for some time and provides relatively high performance for the segment. Part of the reason for the wide adoption of the high-powered Snapdragon 801 is that Qualcomm has not had a convenient SoC offering intermediate between the Snapdragon 801 and Snapdragon 400 (between which exists a large performance and cost gap), and through its control over the high-performance smartphone market through its patent royalty leverage has been able to convince customers to use the Snapdragon 801 in a wide range of devices (as it did previously with the Snapdragon 800), with the SoC providing more performance than really necessary in many cases.

In the OpenGL ES 2.0-based T-Rex (offscreen) test, Snapdragon 801 scores approximately the same as Apple's previous generation Apple A7 SoC. Samsung's recent Exynos 5 Octa (Exynos 5430, with Mali-T628 MP6) used in the Galaxy Alpha also score about the same. The results for the OpenGL ES 3.0-based Manhattan benchmark are also comparable for these three SoCs.

PowerVR's Rogue Han (G6200) GPU with two clusters inside MediaTek's recent MT6595 does not match the performance of the other high-end chips mentioned above, although still providing perfomance clearly above current and upcoming mid-range solutions. This GPU is also implemented in Allwinner's A80 chip, which shows somewhat lower scores in a benchmark entry for an A80 OptimusBoard development board.

Cost-sensitive SoCs: Snapdragon 410 vs Snapdragon 400 vs MT6582

Rather than showing an evolutionary improvement in GPU performance, the quad-core Cortex-A53-based Snapdragon 410's Adreno 306 GPU actually shows 10% to 20% lower GPU performance than the Adreno 305 in Snapdragon 400 based on metrics like fillrate and the offscreen T-Rex benchmark. This provides evidence that Snapdragon 410 is also a cost-reduction effort in comparison with Snapdragon 400, with a smaller die size for the GPU to reduce cost. This also helps to explain why Qualcomm has aggressively pitched the Snapdragon 410 for low-end 4G smartphones as well as somewhat higher segments, with Snapdragon 410 reported to be Qualcomm's current main volume driver.

When looking at previous generation chips, the Adreno 305 in Snapdragon 400 scores higher than MediaTek's MT6582 in the offscreen T-Rex benchmark (approximately 40% better), while some low-level metrics are slower than MT6582. For example, GFXBench's Driver Overhead score is relatively low for both Snapdragon 400 and Snapdragon 410, reflecting mediocre performance when rendering lots of small objects. The fillrate benchmark is also a little lower than MT6582. The higher T-Rex benchmark performance is probably due to a more optimized and larger cache memory subsystems used in Snapdragon 400 and 410. Exactly how Snapdragon 400/410 compares with the MT6582 and other solutions in other benchmarks and games is beyond the scope of this article.

The next generation of efficient Cortex-A53-based mid-range SoCs: Snapdragon 610 and 615, MT6732 and MT6752

Several new chips for the mid-range performance segment are emerging that use a quad or octa-core Cortex-A53 CPU configuration. The use of Cortex-A53 cores at a relatively high clock frequency is promising to significantly improve power efficiency and cost for this segment (which might previously have required the use of more costly SoCs such as Snapdragon 801). This CPU configuration provides adequate single-core performance and (in the case of an octa-core CPU) great multi-core performance.

Both Qualcomm and MediaTek have introduced SoCs in this class, which also introduce new GPU architectures. Qualcomm's Snapdragon 610 (quad-core Cortex-A53) and Snapdragon 615 (octa-core Cortex-A53) utilize the new Adreno 405 GPU, while MediaTek's quad-core MT6732 and octa-core MT6752 utilize a Mali-T760 MP2 GPU (Mali-T760 has also been adopted by Samsung and others).

T-Rex offscreen performance of Snapdragon 615's Adreno 405 GPU (as represented by an entry for a Lenovo device) with a score of about 850 clearly puts the chip in the performance-oriented segment, since Snapdragon 400 and 410 score not much more than 300 in this benchmark. The OpenGL ES 3.0 Manhattan offscreen benchmark score is similarly significantly higher (about three times higher than Snapdragon 400/410). Low-level metrics are all fairly high for a mid-range device, with only fillrate being limited by the 32-bit DRAM interface.

MediaTek's MT6752 with Mali-T760 MP2 (as represented by a Gionee device entry) shows scores for T-Rex and Manhattan that are comparable with Snapdragon 615. Raw low-level metrics such as ALU, Alpha Blending and fillrate are clearly lower than Snapdragon 615, with only Driver Overhead being superior, suggesting that new ARM optimization technologies such as ARM Framebuffer Compression, Smart Composition Transaction Elimination are already having a positive effect on real-world performance, especially within the bounds of a 32-bit DRAM interface, keeping device cost down.

In terms of cost, the ability of MediaTek's MT6752 to provide good performance for a mid-range device, comparable to Snapdagon 615, with an economical 32-bit DRAM interface, make the chip look very attractive. This also provides evidence that ARM has made somewhat of a breakthrough in terms of performance efficiency with Mali-T760 and the associated optimization techniques mentioned above, mostly based on compression techniques, which will revolutionize performance for economical devices with a 32-bit memory interface that have limited memory bandwidth.

MediaTek's quad-core MT6732 (as represented by an Asus device entry), which also has a Mali-T760 MP2 GPU (but clocked lower than in the MT6752) scores lower but still very respectable (especially for the real-world T-Rex and Manhattan benchmarks) for a mid-range device. There have been reports though suggesting that the Mali-T760's efficiency benefits come at the cost of a relatively large chip die size for a cost-sensitive device, so that a chip such as the MT6732 is not suitable for the high-volume entry-level 4G market (for which Snapdragon 410 is likely to be much more suitable). MediaTek is addressing this with its upcoming MT6735 with cheaper Mali-T720 GPU, which does not appear to offer the bandwidth optimization techniques of the Mali-T760.

MT6592 still has competitive GPU performance

MediaTek's octa-core MT6592 smartphone chip (which was released almost a year ago) with a T-Rex offscreen score in excess of 700 has GPU performance that roughly matches that of the upcoming mid-range chips described above, which are addressing approximately the same segment. The high GPU clock speed of the Mali-450 MP4 GPU probably drives the high scores.

The disadvantages of the MT6592 are a lack of OpenGL ES 3.x support and a likely greater memory bandwidth bottleneck when running at high screen resolutions such as 1920x1080, which also impacts power efficiency. GFXBench's battery life benchmarks when running T-Rex long-term are mediocre for most MT6592-based devices, including devices using a 1280x720 resolution, although it is likely that less demanding 3D applications exhibit better battery life. The Cortex-A7 CPU cores (typically clocked at 1.7 GHz) are also slower than the eight Cortex-A53 cores inside a chip like the MT6752 (but still provide plenty of performance).

RK3288's Mali-T764 GPU: Exact nature unclear

Rockchip's RK3288 is a relatively high performance SoC intended primarily for tablets but currently mainly implemented in devices such as media boxes and development boards. For a long time, Rockchip has advertised its RK3288 SoC as featuring an ARM Mali-T764 GPU. This is confusing because ARM has never announced a GPU with that name. ARM's Mali-T760, also used in new SoCs from other companies such as Exynos 5433 (Exynos 7 Octa) and several new MediaTek SoCs, comes close, and one could assume Rockchip means a Mali-T760 MP4 configuration.

However, in the GFXBench results database, all device entries (mainly representing Android TV box devices, but also including tablets such as the Teclast P90HD) for the RK3288 show a set of GL_EXTENSIONS that is identical to that of devices with a Mali-T628 or Mali-T624 GPU. In particular, the GL_EXT_disjoint_timer_query, GL_EXT_sRGB and GL_EXT_sRGB_write_control extensions, which seem to be associated with Mali-T760-class devices, are missing. Whether this means that the RK3288 actually does not contain a Mali-T760-class GPU but instead an older generation Mali-T62x GPU, or this simply reflects non-optimal drivers, is unclear, but there certainly is a suggestion that the GPU inside the RK3288 is actually of an older (Mali-T62x generation) type.

Earlier, Rockchip was not exactly forthcoming about the exact CPU cores inside the RK3288, which have been proven to be Cortex-A12 instead of Cortex-A17, even though ARM later helped Rockchip by declaring that Cortex-A12 will be also referred to as Cortex-A17 (even though it is technically a different core for which Rockchip was one of the few known customers), and CPU performance from benchmarks such as Geekbench suggests the version of the Cortex-A12 core inside the RK3288 does not quite perform as fast as a real Cortex-A17, clock-for-clock.

While RK3288 does support OpenGL ES 3.0 (as do both Mali-T62x and Mali-T760), GFXBench does not allow the OpenGL ES 3.0 Manhattan benchmark to run on this chip for several TV box devices, which one would normally expect to be possible even if the GPU is technically Mali-T62x class. However, the Teclast P90HD tablet entry does show Manhattan benchmark results, which are consistent with a Mali-T62x MP4 GPU (or perhaps Mali-T7xx) configuration, while also showing reasonable sustained GPU performance and power efficiency.

Other tablet solutions

MediaTek's MT8382 chip for 3G tablets shows performance similar to that of the MT6582 smartphone chip, as expected, with a T-Rex offscreen score of about 220. MediaTek's previous generation WiFi-only MT8125 with PowerVR 544MP shows limited performance, lower than Mali-400 MP2 based designs, and slightly less than its previous-generation MT6589T smartphone chip with a similar GPU.

MediaTek's WiFi-only MT8127 with Mali-450 MP4 for somewhat higher performing tablets, shows higher performance with a T-Rex offscreen score of about 500, higher than the typical score of 350 of the popular RK3188T with Mali-400 MP4, which has commonly been used in tablets. However, the performance of the Mali-450 MP4 GPU appears to be clearly lower than the similar GPU configuration in the octa-core MT6592 smartphone chip, which scores more than 700 in T-Rex offscreen and scores higher in low-level metrics such as fillrate, probably due to the lower GPU clock speed of the MT8127. The MT8135V used in recent Amazon Kindle Fire tablets shows good mid-range performance with a T-Rex offscreen score of 740. This results in good performance given the low screen resolution of the Kindle tablets, but performance is otherwise low for a PowerVR Rogue class GPU.

As mentioned, Rockchip's popular RK3188T chip with Mali-400 MP4 clocked at about 400 MHz scores about 350 in T-Rex offscreen, which is a higher than typical cost-sensitive tablet processors, and also scores higher in low-level metrics such as fillrate.

Thanks to the PowerVR 544 MP2 GPU, Allwinner's aging A31s processor still shows higher performance than Mali-400 MP2-based chips such as MT8382. Allwinner's more recent mass-market chips such as A23 and A33 with Mali-400 MP2 have been slow to come to market, and I haven't yet analyzed their GPU performance, but it is unlikely to be spectacular.

An entry for Leadcore's L1860 with Mali-T628 MP2 GPU shows a T-Rex offscreen score of about 580, and it is compatible with OpenGL ES 3.0. The score reflects a fillrate that might still allow higher resolutions such as 1920x1080 to be used in tablets using this chip, with reasonable but not great GPU performance to be expected, helped by a relatively high GPU clock speed.

Intel' s Atom Z3745 processor for the tablet market shows high performance for its class, with the Acer A1-840 FHD (which uses the higher-end Z3745F variant with 64-bit memory interface) scoring a fairly impressive 1181 in the T-Rex offscreen benchmark. The more commonly used cost-sensitive Z3745G with 32-bit memory interface, as used in the Acer A1-840, scores a still very reasonable 853 in T-Rex offscreen. Both processors have relatively good OpenGL ES 3.0 performance, resulting in relatively high Manhattan benchmark scores for their class (higher than chips such as Snapdragon 610/615).

Finally, the results for the Actions ATM7021, a fairly recent ultra-low-end tablet processor, shows signs of blatant benchmark cheating, with the offscreen (1920x1080) T-Rex score being several times higher than the on-screen score for a device with a screen resolution of 1024x768 (one would expect the offscreen score to be several times lower).

Note about T-Rex benchmark and cost-sensitive GPUs

Because GFXBench's T-Rex benchmark targets a fairly detailed and advanced level of rendering that requires a reasonably high-end GPU for good results, the T-Rex benchmark is likely to understate practical GPU performance for low-end devices. Part of the reason for this is the much lower L2 cache associated with low-end GPU like Mali-400 MP2 and especially Mali-400 MP, which is not likely to be enough to satisfy the T-Rex benchmark's relatively large textures and other demands, resulting in much more expensive external RAM access and a relatively low benchmark score. More typical, less demanding GPU applications of the Angry Birds and Temple Run-type are likely to perform better in relative terms on these platforms (although there will still be variation between chips), and GFXBench's low-level benchmarks provide some information on this.

GFXBench's battery life benchmark is also likely to understate practical battery life for devices such as Mali-400 MP and probably Mali-450 MP because of its higher than typical rendering complexity and relatively large texture working set, with battery life for less demanding GPU applications likely to be significantly better.

Sources: GFXBench results database

Updated December 4, 2014 (Make corrections and add comments about Snapdragon 615's 64-bit memory interface vs MT6752's 32-bit memory interface), add section about T-Rex benchmark's complexity negatively affecting low-end CPU scores.
Updated December 25, 2014 (Correct Snapdragon 615 memory interface width).
Updated December 26, 2014 (Provide slightly updated, sorted GPU benchmark results tables).

Samsung and Apple reach agreement for supply of future Apple processors

According to an article published by the Korea Times on November 17, 2014, Samsung and Apple have reached an agreement for the supply of future Apple application processors. The agreement is reported to involve Samsung supplying 80% of Apple's application processors in 2016. The fact that GlobalFoundries has also aligned with Samsung's 14nm FinFET process technology is cited as an additional motivation for Apple, in order to eliminate production capacity concerns.

Agreement will take a long time to come to fruition

However, it is clear from the article that this is long-term agreement that will take considerable time to bring financial benefits to Samsung and involves potential risks and delays given the technological advancements involved in Samsung's new 14nm FinFET process. A research report quoted in the article notes that Samsung's 14nm process for external customers will only start to contribute in the second half of 2015, illustrating that mass production for customers such as Apple is still some way off.

Given the high amount of investment required to bring its advanced 14nm FinFET process to high volume production, it is obvious that Samsung needs clear commitments from third parties that will utilize the process with significant volume. In the article, apart from Apple, Qualcomm and NVIDIA are also mentioned as potential customers.

TSMC continues to benefit from its existing leadership position

Meanwhile, TSMC, which is manufacturing Apple's current generation A8 and A8X and may also produce additional next-generation Apple chips before the Samsung agreement bears fruit, will continue to to benefit from supplying the vast majority of Apple's chips for some time, starting from its current 20nm production. Even though TSMC's 16nm FinFET process technology (evolving from 16FF to 16FF+) is less advanced in terms of feature size than Samsung's 14nm process, its more evolutionary nature most likely will allow TSMC to ramp to stable production much earlier and more smoothly (see also my earlier article), with Apple interested in using it, just as most other major SoC players. In fact Apple was reported to have a signed a multi-year deal with TSMC last year including not only TSMC's 20nm process but also its 16nm FinFET technology.

Capacity constraints at TSMC may disappear

There is also potential for the current shortage of wafer capacity at TSMC to become much less acute in the future, which would diminish one of the main motivations for Apple and other companies to invest in Samsung's production capacity. DigiTimes has already reported that chip orders for Apple's current latest generation devices have reached their peak and are already declining, which may result in a less constrained capacity environment at TSMC in the near term.

Transition to more cost-effective SoCs for performance-oriented segment may reduce wafer requirements

Another potential reason for less wafer capacity requirements at TSMC in the near future is the transition in the performance-oriented segment of the smartphone SoC market from large die size, relatively costly chip platforms such as Qualcomm's Snapdragon 800 series (more or less comparable to Apple's SoCs in terms of cost) to more economical Cortex-A53-based SoCs such as Snapdragon 610, Snapdragon 615 and MediaTek's next generation of chips.

Currently, Qualcomm supplies the Snapdragon 800 series to a large part of the market (even for segments for which its performance is greater than required) because it is less affected by the cost of the chip because of the large margins it achieves through its patent royalty schemes, as well as a performance gap in its product lines of SoCs with integrated modem. However, even for Qualcomm transitioning to less costly chips has the potential to increase profits, and in the past Qualcomm has already benefited from a somewhat similar transition to ARM's economical Cortex-A7 processor core for cost-sensitive platforms.

The new Cortex-A53-based SoCs have the potential to provide performance that is adequate for a large part of the performance segment, while being power efficient and due to the smaller die size may significantly reduce the total number of wafers required for performance-oriented smartphone SoCs.

Sources: Korea Times article, Blog article from 3 October

Updated December 5, 2014.

Samsung's 64-bit Exynos 5433 SoC renamed to Exynos 7 Octa, used in some Galaxy Note 4 models

Recently, Samsung renamed its Exynos 5433 SoC to Exynos 7 Octa. The new Exynos chip is used by Samsung in the new Galaxy Note 4 smartphone, although how material actual shipments are has been unclear because most regions were first served primarily by Qualcomm Snapdragon 805-based versions of the Galaxy Note 4. However, evidence from the Geekbench result database suggests roughly a quarter of models currently sold are Exynos versions.

Signs of actual adoption of Exynos 7 Octa in high volume becoming apparent

Samsung has in the past frequently announced the use of Exynos SoCs in prominent smartphones, but shipments were often limited to very low volumes for smaller regions such Korea, with the vast majority of shipments using Snapdragon SoCs. During the last two years, only Samsung's tablets have seen widespread use of Samsung high-performance mobile SoCs. Although Samsung has recently ramped mid-range chips such as Exynos 3470 in presumably high volume for the Galaxy S5 Mini, strong evidence would be required to establish that the situation will be different this time around in terms of a high profile Exynos SoC (Exynos 7 Octa) being actually used in high volume in smartphones.

However,  searching for Galaxy Note 4 models on the Geekbench Browser provides evidence that at least one quarter of units currently sold contains the new Exynos chip, with the other three quarters or so using Snapdragon 805. Exynos versions are primarily represented by the SM-N910C, SM-N910S and SM-N910K models, while Snapdragon versions are mainly represented by SM-N910A, SM-N910T, SM-N910F and several other models.

Number of Geekbench entries for each Samsung Galaxy Note variant as of 24 October:

• SM-N9100: Snapdragon 805, 7 entries
• SM-N9109W: Snapdragon 805, 4 entries
• SM-N910A: Snapdragon 805,  635 entries
• SM-N910C: Exynos 5433, 425 entries
• SM-N910F: Snapdragon 805, 496 entries
• SM-N910H: Exynos 5433, 24 entries
• SM-N910K: Exynos 5433, 73 entries
• SM-N910L: Exynos 5433, 33 entries
• SM-N910R4: Snapdragon 805, 23 entries
• SM-N910P: Snapdragon 805, 238 entries
• SM-N910S: Exynos 5433, 197 entries
• SM-N910T: Snapdragon 805, 559 entries
• SM-N910V: Snapdragon 805, 69 entries
• SM-N910W8: Snapdragon 805, 10 entries

For the listed models, the total count is 752 Exynos and 2041 Snapdragon, representing an Exynos proportion of about 27%.

All things being equal, one would expect Samsung to prefer to use the internally manufactured Exynos chipset if enough supply is available, although with four Cortex-A57 cores the SoC is likely to be relatively expensive to manufacture. On the other hand, there are significant performance differences, with the Exynos platform clearly faster in terms of CPU processing but with a question mark in terms of power efficiency, while Snapdragon 805 can be regarded as mature, stable technology. Qualcomm may also be able to enforce a certain quotum of Snapdragon chips based on its leverage of patent royalties and licensing fees (which are considerable for a high-end smartphone).

Some anomalies are evident in the chips used for certain models. For example, a number of the SM-N910S results (which officially uses the Exynos 5433) in the Geekbench database show the use of an APQ8064 (Snapdragon 600) SoC clocked at 1.89 GHz, which is significantly slower that Exynos 5433 (or Snapdragon 805). Similarly, for the SM-N910C, starting from October 30 a not insignificant number of results labelled as SM-N910C show the use of the aging Exynos 4412 SoC (also used in old models such as the Galaxy S III) with four Cortex-A9 cores clocked at 2.0 GHz, much slower than Exynos 5433. These anomalies probably represent counterfeit production by Chinese manufacturers (both APQ8064 and Exynos 4412 have been common in the supply chain in the past). For models that officially use Snapdragon 805, no anomalies are evident.

Update as of December 5, 2014

Reassessing the share of Exynos 5433 vs Snapdragon 805 in the Geekbench database after a few months of production should be informative about whether Samsung is really serious about ramping Exynos production for smartphones. The following is apparent:

• The Exynos-based SM-N910C count has increased from 425 to 4390.
• The Exynos-based SM-N910S count has increased from 197 to 578.
• The Exynos-based SM-N910K count has increased from 73 to 212.
• The Exynos-based SM-N910H has increased from 23 to 757, while SM-N910L has increased from 33 to 91.
• The new Exynos-based SM-N910U shows a count of 1062.
• The Snapdragon 805-based SM-N910A count has increased from 635 to 2258.
• The Snapdragon 805-based SM-N910T count has increased from 559 to 2089.
• The Snapdragon 805-based SM-N910F count has increased from to 496 to 3857.
• The Snapdragon 805-baed SM-N910P count has increased from 238 to 1162.
• The Snapdragon 805-based SM-N910R4 has increased from 23 to 61, SM-N9100 from 7 to 58, SM-9109W from 4 to 20, SM-910V from 69 to 1685, and SM-910W8 from 10 to 636.
• The new Snapdragon 805-based SM-N910G shows a count of 903, SM-N9106W shows 22, SM-N9108V shows 1.

For the listed models, the total count is 7090 Exynos and 12752 Snapdragon, representing an increased share of Exynos-based models in the Geekbench database from about 27% to about 36%, clearly suggesting that the share of Exynos-based models is increasing, and recent production may already have a much greater proportion of Exynos-based models.

First 20nm ARMv8 SoC targeting Android

One of the first smartphone SoCs manufactured using a 20nm process, at Samsung's own fabs, the Exynos 7 Octa is the first chip featuring ARM's Cortex-A57 and Cortex-A53 cores in a big.LITTLE configuration to appear on the market. The Cortex-A5x cores support the 64-bit ARMv8 instruction set, although using the 32-bit variant of the ARMv8 instruction set also appears to bring benefits while avoiding the performance degradation (related to increased memory use for pointers and addressing) that is associated with going to full 64-bit.

It is not the first 20nm SoC to support the ARMv8 instruction set, since Apple's A8 chip has already ramped to high-volume production during most of the year at TSMC for use in the iPhone 6 models. And already in 2013, Apple introduced the first ARMv8 chip with the Apple A7. As I have explained in an earlier article, there are reasons to believe the CPU cores in the Apple A7/A8 may have great similarities to ARM's Cortex-A57 CPU core, and in that sense the Exynos 7 Octa technically may not actually be the first SoC with Cortex-A57 cores to hit the market.

Fast, but power efficiency may be a problem

Reviews of Exynos 7 Octa-based devices such as the Galaxy Note 4 are still scarce. Already several months ago, early benchmarks results showed Exynos 5433 (as it was known then) providing the highest performance in the mobile space, significantly outscoring Snapdragon 805 in most benchmarks. This is not unexpected given the use of high-performance Cortex-A57 cores at a fairly high clock frequency.

However, there are signs that maintaining power efficiency with higher-clocked Cortex-A57 cores may be a challenge. Some early hands-on preview have suggested relatively high power consumption and mediocre battery life for an Exynos 5433-based Galaxy Note 4. More definite test results should clarify the situation.

Setting maximum clock frequency creates dilemma

Software techniques such as the use of efficient Global Task Switching with preference for the economical Cortex-A53 cores and throttling down of the clock frequency may be vital to maintain acceptable battery life. Analysis of Geekbench results for the Exynos 5433-based SM-N910C shows a multi-core performance scaling factor of about 4.45 for the largely CPU-bound JPEG Compress test, suggesting that Global Task Switching is implemented in such a way that not just the Cortex-A57 cores are utilized but the Cortex-A53 cores as well when high CPU performance is required.

High-performance CPU cores such as Cortex-A57 tend to have relatively high power consumption that increases as the clock frequency increases. This creates a dilemma for a manufacturer, because for acceptable power consumption with practical use there is little reason to set the maximum clock speed at the relatively high level that desirable for marketing purposes; a speed similar to the one used in Apple's Cyclone cores (e.g. 1.4 GHz) provides more than enough speed for most applications while limiting the excessive power consumption (and potential stability problems) associated with higher frequencies. A similar dilemma is often associated with SoCs with Cortex-A15 CPU cores (such as Samsung's Exynos 5430 used in the Galaxy Alpha) that have performance characteristics (high performance, but low performance/Watt) comparable to Cortex-A57, although Cortex-A57 is likely be more efficient.

Providing superior synthetic benchmark performance can be a matter of high prestige for a company and its marketing department to the extent that an unbalanced high maximum clock frequency may still be used in actually shipping devices, to the detriment of the user experience. Associated with this dilemma is the attraction of "cheating" on benchmarks by detecting when synthetic benchmarks are run and the switching to higher, sustained clock frequencies with reduced heat throttling, which has been demonstrated to be widespread in the past by websites such as AnandTech.

Evidence suggests Exynos 5433's Cortex-A57 cores are already clocked at a relatively low but efficient speed of about 1.4 GHz

Exynos 5433 may in practice already be clocked at a relatively low maximum speed to conserve power. Geekbench consistently reports 1.3 GHz as the clock frequency for all Exynos 5433 devices, however for some devices, including Samsung's big.LITTLE Exynos 5430 with Cortex-A15, Geekbench seems to report the maximum clock speed of the slower LITTLE cores, so the Cortex-A57 are probably clocked higher. However, even for the Cortex-A57 cores in the Exynos 5433, which have dramatically higher performance/cycle than the LITTLE Cortex-A53 cores, a relatively limited maximum speed in the range of 1.3 GHz would by no means be inappropriate for a smartphone platform.

Looking more closely at cross-platform Geekbench results for the Exynos-based Note 4 and the iPhone 5S and iPhone 6, and assuming that Apple' s Cyclone and Cortex-A57 are cores with similar performance characteristics at given clock speed (at least the little available evidence puts metrics like IPC and DMIPS in the same ballpark), gives indications that Exynos 5433 may on average actually be clocked at an effective 1.4 GHz, comparable to the 1.4 GHz of the iPhone 6. However, it can not be ruled out that in the case of the Exynos 5433 the frequency is the average resulting from thermal speed throttling (variation of the CPU speed based on power consumption and heat production).

Apple's SoC architecture is also different because it is a dual-core compared to the big.LITTLE configuration of the Exynos 5433 with four Cortex-A57 cores and four Cortex-A53 cores, and Apple' s cache memory architecture is very different with a large L3 cache and likely highly optimized but smaller L2 cache, and the Apple device has higher external RAM performance. Additionally, the software model (Apple's  64-bit AArch64 vs 32-bit ARMv8 AArch32 used with Exynos 5433) also complicates things, however some conclusions may still be drawn looking at specific benchmarks.

Comparison with Apple A7 and A8 benchmarks provides clues

Performing a detailed comparison of representative results for a SM-N910C and an iPhone 6 with Apple A8 on the Geekbench browser page provides interesting information. On first glance the results are all over the place with some benchmarks (including single-core ones) being faster on Exynos and others on the Apple A8, while Exynos obviously has an advantage for multi-core tests.

However, one can look for sub-benchmarks that are less likely to be affected by a large L3 cache on the Apple device, specifically benchmarks that do not have a large memory working set and source data or do not constantly perform random read access on a large set but do perform a lot of processing, possibly writing (but not reading) a lot of data. Some stream-type algorithms such as common data and image compression and decompression benchmarks fit the bill, because they generally steam the source data sequentially, perform a relatively high amount of CPU processing based on a relatively limited working set (a small part of the stream/file), and write the resulting data sequentially.

This type of benchmark puts the Exynos 5433 somewhat lower but fairly close to the Apple A8 in single-core CPU performance. Further information can be gained from iPhone 5S (Apple A7) results.

Benchmark results: Galaxy Note 4 (SM-N910C) vs iPhone 5S vs iPhone 6, relative speed advantage of iPhones compared to SM-N910C:

Test name                           SM-N910C  iPhone 5S       iPhone 6
BZip2 Compress:                     1187      1109 ( -6.5%)   1187 ( +8.5%)
BZip2 Decompress:                   1366      1394 ( +2.0%)   1538 (+12.6%)
JPEG Compress:                      1378      1196 (-13.2%)   1372 ( -0.0%)
JPEG Decompress:                    1598      1583 ( -0.9%)   1855 (+16.1%)
PNG Compress:                       1391      1427 ( +2.6%)   1577 (+13.4%)
PNG Decompress:                     1490      1301 (-12.7%)   1498 ( +0.5%)
Sobel (image local edge detection): 1701      1584 ( -6.9%)   1922 (+13.0%)

The Apple A8 chip in the iPhone 6 scores somewhat higher than Exynos 5433 in most tests, while Exynos 5433 is on average faster than the Apple A7 in the iPhone 5S. All of this is consistent with the CPU cores in all of the devices having comparable single-core CPU performance, and when making the assumption that Cortex-A57 and Cyclone (which seems to have a lot of architectural similarities with Cortex-A57) have comparable performance per cycle (at a given clock frequency), consistent with a clock frequency for the Exynos 5433 that is similar to the one used in the Apple devices (around 1.3 to 1.4 GHz).

The largely CPU-bound JPEG Compress test, which appears to be closedly tied to clock speed on other chip platforms with limited dependence on factors outside the CPU core, provides evidence that the isolated single-core CPU performance of Exynos 5433 may be close to that of the Apple A8 in the iPhone 6, consistent with a similar effective clock frequency of about 1.4 GHz. To what extent thermal throttling plays a role for the Exynos is not entirely clear. Most of the Geekbench results for SM-N910C for the JPEG Compress test are very close (a score around 1375), suggesting that at least for this test the maximum clock speed is generally maintained, which would be compatible with this speed being about 1.4 GHz.

PNG Decompress seems to be somewhat of a negative outlier for the Apple A7 and A8, but it is consistent across different iPhone results and is probably related to the high amount of memory writes (decompressed image data) associated with the benchmark, which can be affected by the extra layer in the memory subsystem represented by the L3 cache.

One significant caveat for the comparison above is that the Apple devices run in AArch64 mode, while Exynos 5433 in the Note 4 runs in AArch32 mode (the 32-bit version of the ARMv8 instruction set). AArch64 can take advantage of more instructions, in particular instructions operating on 64-bit registers, while the increased pointer/address storage size can decrease performance somewhat. However, the source code for the Geekbench test is likely to be identical (without extensive use of 64-bit integer variables) for AArch64 and unlikely to be specifically optimized, with any optimizations for AArch64 in the generated code depending on the compiler.

Sources: Samsung (Exynos 7 Octa), Geekbench Browser

Updated (24 October 2014): Update with information about proportion of Exynos models based on Geekbench database, and provide performance comparisons with Apple processors.
Updated (30 October 2014): Language tweaks, improve Geekbench comparison table and fix PNG Decompress score for iPhone 5S.
Updated (2 November 2014): Update discussion about clock speed of Exynos 5433, expand description of use of GTS, make note of counterfeit models in Geekbench database.
Updateed (5 December 2014): Update Exynos model share statistics for Galaxy Note 4.

Transition to next-generation FinFET process nodes: Samsung unlikely to be in the lead despite media reports

In the last few months, relatively vague media reports about Samsung gaining back chip orders from Apple that it has recently lost to TSMC, as well new orders for Qualcomm and other players for its next-generation 14nm FinFET technology have surfaced a few times. These media reports have frequently been widely reported in popular technology publications, often been interpreted as if TSMC would be losing market share in 2015 to the point of having significant excess capacity or as if Samsung has a considerable technology lead. However, these media reports as well sweeping conclusions about a presumed superior market competitiveness of Samsung in comparison with TSMC in 2015 are likely to be highly inaccurate.

TSMC currently dominates advanced node foundry production

TSMC currently dominates the foundry market for leading-edge nodes such as 28 and 20nm for chips such as smartphone SoCs and GPUs with a market share in excess of 80%, and faces significantly more demand than it is able to supply, despite unprecedented investment in new production capacity. Samsung's 28nm logic fabs are currently largely empty, and a similar situation is occurring at GlobalFoundries as it has been struggling to gain significant customers apart from AMD. Within this context, it is apparent that TSMC has been doing something right, while Samsung and GlobalFoundries must have had some significant set-backs, otherwise this market share distribution would not be happening. Given this track record, one can wonder how realistic it is to expect that the level of competitiveness of Samsung and GlobalFoundries would recover or even be reversed for next-generation processes as early as 2015.

Chip design companies motivated to seek additional sources of supply, but challenges apparent

Clearly, because TSMC currently has a virtual monopoly and is not able to fulfill demand there is a pressing motivation for chip companies such as Qualcomm and others to seek additional sources of supply. Therefore there is no reason to doubt that major efforts are being made in this area, especially starting from about Q2 2014 when the capacity shortage at TSMC became very evident. However, successful completion within any reasonable time-frame of such a move (especially when the effort has only recently become more intensive) involves substantial technological challenges and risks, which make it unlikely that it will actually happen in any way close to the time-frame and volume that has been suggested be some reports.

The fact that TSMC's 16nm FinFET process is an evolutionary extension of its already highly successful 20nm process to incorporate FinFET technology, rather than the radical technology changes involved in Samsung's 14mn FinFET process, also make it likely that chip design companies will continue to concentrate on TSMC process technology in the near term out of necessity, with any efforts with Samsung likely to only result in significant production at a much later stage.

Optimistic projections from sources within Samsung widely reported as fact

In an article on October 1, ZDNet (based on an article from its Korean website) quotes a manager from Samsung's LSI division saying that Samsung is likely to improve profits once it achieves volume production for next-generation products for Apple. The source declined to comment about when Samsung would start mass producing such chips for clients. Combining earlier media speculation, the article goes on to state that 14nm production for clients such as Apple, Qualcomm and AMD would start as early as the end of this year. The article also quotes undisclosed sources that Samsung is producing 30% of Apple's A8 processors, with the rest being manufactured by TSMC. The article has been widely quoted in popular news media.

However, there are several reasons to believe that these reports are relatively inaccurate and misleading. First of all, unofficial remarks from sources within Samsung seem to be the only source of information for the article. As mentioned in the article, Samsung is currently incurring very significant losses from its logic (LSI) fabs because of underutilization after losing Apple SoC orders to TSMC. That sources within Samsung (including managers who in fact may hold primary responsibility within Samsung for achieving profitability of the LSI division) would be inclined to paint to an over-optimistic picture that may not accurately reflect the the current and future market status for production of advanced next-generation designs is not at all surprising.

Apple has explored multiple sources for production of Apple A9

Already in July 2013, an article published by EE Times reported that Apple signed a deal with Samsung with Apple to produce the Apple A9 in 2015.  This article also illustrates that knowledge of TSMC 20nm production for the Apple A8 in 2014 (as mentioned in the article) was already widespread at this time. However, in June 2013, it was already reported that Apple signed a three-year deal with TSMC not only involving 20nm, but also TSMC's next-generation 16nm FinFET and later 10nm FinFET technologies, with Apple A9 being mentioned. Recently, in August 2014, DigiTimes reported that TSMC had gained production of the Apple A9 using its 16nm FinFET process with significant volume as early as Q1 2015. More recent reports suggest Apple A9 will be manufactured at TSMC but using the same 20nm process as Apple A8.

Based on TSMC's track record and in particular its successful high volume ramp of the Apple A8 using its 20nm process, I believe it is very likely that Apple will focus Apple A9 production, at least for the most significant earlier part of its production cycle, at TSMC. Apple will be able to move to FinFET earlier at TSMC if it chooses too because TSMC's 16nm FinFET is to a large extent an evolutionary extension of its 20nm process incorporating FinFET technology, rather than the radical technology change involved in Samsung's 14mn FinFET process, achievement of maturity for high volume production is much less of a challenge which makes it unlikely that Samsung will be able to achieve a similar level of maturity in a time-frame that is competitive with TSMC. The fact that qualifying and bringing a similar chip to stable production at Samsung involves substantial additional investment in chip design, testing and associated risks including the timing of such production will probably even make it attractive for Apple to keep material Apple A9 production at TSMC for its entire life cycle.

Achieving significant production of Apple A8 will be very challenging for Samsung

In addition, the accuracy of the claim that 30% of the production of the Apple A8 is already manufactured by Samsung is highly questionable. Samsung's 20nm process is fundamentally different from that of TSMC in several details, and Apple would have to repeat most of the design/validation cycle that it is has already completed for the TSMC version of Apple A8 in order to be able to produce at Samsung's fabs, resulting in very high additional cost, numerous risks, and substantial delays. Moreover, it is doubtful that the production capacity of Samsung at 20nm (which it already uses for certain Exynos chips such as Exynos 5430 and 5433, and even those do not appear to have already ramped in really high volumes) is ramping fast enough to quickly gain material shipments to Apple, especially when Samsung is supposed to be rapidly transitioning to 14nm FinFET.

While it is not unlikely that Samsung has been aggressively seeking to provide capacity for the Apple A8, working with Apple, whether it would be able to achieve material amounts of production before the latter stages of the life cycle of the Apple A8 in 2015 when production levels will already have decreased is debatable. From Apple's viewpoint, it appears that its relationship with TSMC involves TSMC giving it any level of capacity it needs (to the detriment of competitors who are facing wafer shortages) which makes the apparent benefit for Apple to quickly move part of the Apple A8 production Samsung relatively limited. Samsung may offer lower prices for 20nm manufacturing capacity, but as explained earlier, the complexity, cost, time and risk involved in moving Apple A8 production to Samsung make it unlikely that Samsung will be able to gain a significant share of production within a reasonable time-frame.

Comparison of FinFET technologies at Intel, TSMC and Samsung

Recently, ZDNet also published a much more technical and reliable article discussing the status of FinFET technologies of the major fab players, including Intel, TSMC, Samsung and GlobalFoundries.

Intel started production of processors using FinFET technology at 22nm as early as 2011 and has already shipped 500 million such chips, mostly targeted at PCs but also gaining shipments for tablet applications this year. It also offers the technology to other customers as a foundry. Intel has started volume production of its next-generation 14nm FinFET process, which is a "true shrink" with significantly increased transistor density and delivers a combined 1.6x improvement in performance/Watt across applications ranging from smartphones to servers, and will continue to ramp production into 2015.

TSMC's 16nm FinFET development is at an advanced stage

TSMC's first generation 16nm FinFET process, 16FF, was qualified in November 2013 and already saw product tape-outs as early as April 2014. This suggests TSMC's 16nm FinFET process is already close to high volume production. TSMC's 16FF process will be followed up by its 16FF+ process with tape-outs expected in early 2015. While the performance benefits of 16FF are limited due its similarities (the same back-end metal layers) with TSMC's 20nm process, the 16FF+ process involves a reduction in feature size that makes it competitive with the theoretical performance of 14nm FinFET processes from competitors. TSMC is already in a stage called "risk production" for 15 16nm FinFET products this year and another 45 products next year for a variety of applications. Yields are reported have already reached levels comparable to TSMC's 20nm process. This is not surprising, as TSMC has reported that 95% of the tools used for 20nm can be reused for 16FF, which also brings massive advantages in the required level of investment to ramp capacity and greatly facilitates time-to-market.

TSMC quotes its 16FF+ process as having 15% greater performance when compared to 16FF (40% compared to 20nm) and 30% less power consumption when compared to 16FF. TSMC is already working on 10nm FinFET process technology which involves a more substantial 2.2x increase in transistor density.

SoCs using Cortex-A57 and Cortex-A53 CPU cores already implement TSMC's 16nm FinFET processes

Although 16FF is seen as a stepping stone to FinFET technology, it does provide performance benefits over planar 20nm. TSMC and ARM have announced that a 16nm test chip using Cortex-A57 and Cortex-A53 cores in a big.LITTLE configuration achieved a sustained 2.3GHz clock rate for the Cortex-A57 core with minimal power consumption of 75 milliwatts achieved for the Cortex-A53 core for common workloads. This demonstration involving a currently relevant SoC design illustrates the relative maturity of TSMC's 16nm technology.

For Cortex-A57, 16FF+ is expected to result in a 11% performance improvement relative to 16FF at the same level of power, while power consumption of the Cortex-A53 for low-intensity applications is reduced by 35%. ARM POP IP core hardening (tweaking cores for either performance or low power consumption) is utilized for early 16FF+ SoC designs. Although TSMC does not specifically address the use of Cortex-A53 at higher clock rates for high performance applications instead of Cortex-A57, the quoted numbers are consistent with the better scaling of Cortex-A53 on new processes when compared to performance-oriented "big-core" Cortex-A57 and cores with a similar architecture.

For example, one can speculate that the significant power reduction for the Cortex-A53 will further significantly increase the maximum clock rate and performance of Cortex-A53 CPU cores, more than the 11% quoted for Cortex-A57, making Cortex-A53-only designs more attractive for high-end applications. Already, early reports about MediaTek's MT6795 octa-core SoC running at about 2.2GHz, the first Cortex-A53-based SoC targeting high performance applications, suggest that it will provide premium-level performance at half the price of current premium-performance SoCs. The chip achieves this despite still using 28nm technology, indicating that Cortex-A53-based high-performance designs using more advanced nodes such as 20nm and 16nm FinFET will be even more revolutionary in terms of performance efficiency.

Samsung development of 14nm FinFET well underway, but maturity for high volume production unclear

Production of the first test chip (using a Cortex-A7 CPU core) on Samsung's first generation 14nm FinFET process, 14FPE, already occurred in December 2013. According to the marketing manager for Samsung’s foundry business, the foundry has completed tape-outs of multiple products and has already started early commercial production for some customers. The 14FPE process is claimed to provide either a 20% boost in performance or a 35% reduction in power consumption when compared to be a planar 20nm process. The process is said to result in 15% smaller chips when compared to a 20nm planar process.

Considering the considerable technological changes in Samsung' FinFET process (especially when compared to TSMC's more evolutionary first-generation 16FF process, which is closely aligned with the already almost mature 20nm), the claimed performance and density gains are relatively minor in the context of the high costs and learning curve involved in bringing chips to mature volume production. High theoretical performance of a new process has little value when it involves very high investment in chip design, relatively high manufacturing cost, and when mature volume production is not achieved in a timely manner. A higher performance version of Samsung's 14nm FinFET process, 14LPP, is expected to be qualified in a couple of months time.

Meanwhile, GlobalFoundries has given up on its own 14XM FinFET process and has aligned with Samsung's 14LPE and 14LPP processes. This decision probably means that it will take considerable time before GlobalFoundries will be competitive for volume production using FinFET, providing evidence that its market position will continue to be precarious for some time.

Conclusion

In summary, indications are that TSMC, helped by its more evolutionary transition to FinFET and dominant position in current leading-edge processes, is much closer to stable high volume production of next-generation FinFET processes than Samsung, and that it will continue to dominate leading-edge foundry production in the near term even as chip designers seek additional sources of supply given the very tight capacity environment at TSMC.

While Intel is also well advanced in its FinFET process development and uses it on a large scale for PC processors, it has not yet seen widespread success either as a foundry partner for third parties or as a provider of large numbers of low-power SoC for applications such as smartphones, also illustrated by the fact that early Intel mobile SoCs such as SoFIA that integrate cellular baseband and other components will in fact first be produced at TSMC and not in Intel's own fabs.

Source: ZDNet (Technical article of FinFET technology development), ZDNet (Samsung LSI article), EE Times

Updated October 5, 2014 (Spelling, grammar) .
Updated October 30, 2014 (Grammar, small corrections).
Updated December 26, 2014 (Minor grammatical corrections).

Apple announces iPhone 6 and iPhone 6 Plus using Apple A8 SoC

As expected, Apple announced several new products on September 9, most prominently the iPhone 6 and iPhone 6 Plus smartphones.

The iPhone 6 has a 4.7" LCD screen with a non-standard 750x1334 resolution (slightly higher than 720p), designed for convenient pixel scaling for existing iOS apps. The iPhone 6 Plus has a 5.5" LCD screen with standard 1080x1920 (1080p) resolution. Because of the limited dynamic pixel scaling ability of iOS, for compatibility apps can technically be scaled by a factor of three (from the Apple standard 414x736 to 1242x2208) and then downscaled to 1080p.

Both models are thin smartphones with a thickness of about 7mm. Connectivity has improved, with more LTE bands and support for VoLTE (voice over LTE) and 802.11ac WiFi. LTE is limited to Category 4, unlike certain high-end competitive devices such as the Galaxy Alpha en Galaxy Note 4 that support LTE Category 6.

Apple A8 at 20nm: Modest performance and power improvements

The process improvement from 28nm to 20nm facilitates a transistor count increase (estimated to have doubled from one billion to two billion), resulting in a relatively large chip, even at 20nm, although the reported die size of 89mm² is smaller than the 104mm² of the Apple A7. However, performance improvement compared to the Apple A7 is reported to be relatively moderate. CPU performance improvement quoted by Apple is 25%, with GPU performance (reported to be powered by a PowerVR GX6450 with four clusters) being improved by 50%. Early Geekbench test results show a modest CPU processing improvement (from around 1400 single-core/2500 dual-core on the iPhone 5S to roughly 1630/2920 on the iPhone 6), aided by a relatively minor CPU clock speed increase.

Despite the larger battery size (1810 mAH) in the iPhone 6 vs 1560mAh in the iPhone 5S) allowed by the larger physical dimensions, offset somewhat by increased power use caused by the larger screen, Apple quotes only minor improvement in battery life over the iPhone 5S for most applications (slightly better on the iPhone 6 Plus), which is disappointing since the iPhone 5S's battery life has been a major weak point in practice. However, the iPhone 6 Plus contains a significantly larger 2915 mAh battery which should allow it to have improved battery life compared to the iPhone 6 and iPhone 5S.

It is possible that gains in power efficiency are larger in practice, with the official battery-life specifications coming closer to reality relative to the more optimistic specifications for the iPhone 5S. Apple has been quoted as saying that the Apple A8 draws up to 50% less power than the previous chip (which is a statement open to interpretation, because it does not specify the level of improvement with typical use), and focusing only on the CPU logically the transition to the 20nm TSMC process with a similar configuration and clock speed should result in measurable power savings, all things being equal.

Similar CPU, but transistor count significantly increased

However, the large increase in transistor count (from roughly one to two billion) may be associated with lower power saving benefits than would otherwise be expected from applying more advanced manufacturing process to, for example, similar CPU cores. Exactly what functionality contributes to the transistor count increase is unclear; the GPU and its associated caches should be significantly larger, a requirement because of the increased number of screen pixels, and the L2 CPU cache (1MB in the Apple A7) may have increased performance (although still using the same 1MB size). The Apple A7 has been reported to already contain a large 4MB L3 cache (which uses a lot of transistors/die area) that may have increased in size in the Apple A8 or otherwise have improved performance (CPU caches of a given size can be made better-performing by using more transistors).

AnandTech has reported that L3 cache latency has improved with capacity remaining the same at 4MB, which is consistent with an increase in L3 transistor count, matching the increased proportion of the die used for the L3 cache (roughly half of the chip) on the Apple A8 when compared to the Apple A7 (the L3 cache scales down less than other blocks in the transition to 20nm). What exactly Apple's goal is by including a large L3 cache is unclear, but for applications that have a memory working set that fits entirely into the cache there would be obvious performance and power consumption benefits. Part of the benefit may be allowing most of the display framebuffer to be stored in the L3 cache, reducing memory overhead related to graphics operations and screen refresh, which would be more apparent with higher resolutions such as the iPhone 6 Plus or potentially iPads, although the L3 cache would have to be large enough to hold the actively changing part of the framebuffer (a full 1080p 32-bit framebuffer is 7.9 GB), with the amount of required memory potentially lowered by compression or encoding optimizations.

Instead of integrating the baseband into the SoC, the Apple A8 continues Apple's practice of using an external Qualcomm baseband modem chip (MDM9625M) in combination with the Apple SoC. The MDM9625M is limited to LTE Cat 4 and does not support LTE Cat 6 (Qualcomm already offers new LTE Cat 6 stand-alone modem chips, used with SoCs like the Snapdragon 805). Because it is a separate chip, Apple may be able to provide updated versions of the iPhone 6 with LTE Cat 6 with a relatively minor redesign during its lifetime.

Although few specific details are yet available, reports suggest that the Apple A8 SoC continues to use a CPU configuration similar to that of the Apple A7, most likely a dual-core performance-oriented CPU with CPU cores very similar the Cyclone cores used in the Apple A7, which may be closely related to ARM's Cortex-A57. Reports indicate that CPU performance is close that of the A7 with a modest clock speed increase from 1.3 to 1.4 GHz contributing to  somewhat increased performance. Some of the performance increase is likely to be contributed by speed improvement and/or size increase of the L2 and L3 caches. AnandTech has observed a few micro-architectural cycle time improvements, for example for integer multiplication and floating point addition, contributing to increases in synthetic benchmark scores. In terms of die area, the CPU block on the block has been estimated to have decreased from about 17mm² to 12mm² thanks to the 20nm process

Performance scaling of Cortex-A57-class CPUs and other out-of-order, speculative issue superscalar CPUs

The disappointing performance and power-efficiency scaling of high-performance CPU cores such as Cortex-A15, Cortex-A17 and Cortex-A57, and also the processor core used by Apple in the Apple A8, which all implement out-of-order superscalar pipelines with speculative issue, when transitioning to more advanced processes (such as 28 and 20nm) has already been noted in the industry. Relative to the benefits expected from the more advanced 20nm HPM process at TSMC compared to the Samsung 28nm HKMG process used for Apple's previous processor, the performance increase and and to some extent power efficiency improvement is modest, with potential for clock speed increases apparently limited.

In contrast, small, medium-performance and extremely power-efficient in-order pipeline cores such as Cortex-A53 (and earlier Cortex-A7) are showing dramatically better scaling with newer processes (including advanced 28nm and 20nm processes), with the ability to optimize for performance or power-efficiency with "core hardening", with greater increases in clock speed and the ability to use a many-core (such as octa-core) configuration with limited implications for cost (die size) and power consumption. This results in dramatically better performance/Watt characteristics and much lower chip cost even for high-performance applications, with the only disadvantage being somewhat limited single-thread performance and the requirement of more extensive utilization of multi-threading in the operating system and application software.

Apple A8 still not very power efficient, but larger batteries used

As a result, Apple's new SoC seems to be widening Apple's SoC efficiency deficit when compared to SoCs being introduced in competitive devices, with the Apple A8 being relatively high-cost and uneconomical to manufacture, providing only modest performance improvement despite the larger size and higher cost when compared to the Apple A7, and a significant and increasing disadvantage in power consumption and performance/Watt compared to SoCs from competitors, despite Apple's head start with 20 nm process technology. Although high chip cost is not a major issue for Apple due to its large profit margins, the disadvantage in power efficiency will continue to be reflected in the end-user experience.

However, at least for the 5.5" iPhone 6 Plus, Apple has significantly increased battery capacity to 2915 mAh, much larger than the 1810 mAh battery in the 4.7" iPhone 6 and the 1560 mAh of the iPhone 5S. This will result in improved battery life in the iPhone 6 Plus compared to other recent iPhones, as the increase in capacity more than offsets the somewhat larger power requirement for the screen. Testing of the new iPhone models based on automated battery life benchmarks for light browser shows a competitive score, increased somewhat over iPhone 5S, and more significantly for the iPhone 6 Plus. However, in this type of benchmark, the iPhone 5S already scored higher than what one would expect based on actual battery life in practice, and more detailed battery life benchmarks have been published that indicate battery life of the iPhone 6  models is still rather average compared to the competition.

Memory subsystem in Apple SoCs favors synthetic benchmarks

There seems to be a tendency of recent iPhones (including the previous generation iPhone 5S) to show benchmark scores often near the top of the chart for CPU performance or even battery life in synthetic benchmarks However, in practice (in typical every-day use), performance characteristics, especially battery life, tend to be considerably less than would be expected based only on these benchmarks (competitors that perform similarly in synthetic battery life test tend to have much better practical battery life). Differences in the operating system (iOS versus Android) could be a factor, but characteristics of the memory subsystem of recent iPhones may be the most significant factor affecting battery life.

Large on-chip cache memories (such as the 4MB L3 cache in Apple A7 and A8, unprecedented for a mobile SoC) have long been known in the computing world to result in particularly high scores in certain synthetic benchmarks as long as their memory footprint fits within the cache, positively affecting both CPU performance benchmarks and battery life tests (access of external RAM or flash storage is slower and uses significantly more power). Also well known is the fact that such benefits quickly diminish when a typical memory footprint no longer fits inside the cache, which may not be common for synthetic benchmarks, but may actually be pretty common for every-day use. Moreover, the relatively limited 1GB RAM of the iPhone 6 models results in more frequent flash memory access (e..g. reloading of tabs in Apple's browser, in addition to less visible activity), which can have a strong negative effect on battery life that is not apparent in many synthetic battery life tests.

In summary, the memory subsystem (large on-chip caches and limited RAM) of recent iPhones is likely to be associated with relatively high scores in most synthetic performance and battery life benchmarks that are not fully representative of the practical experience (particularly for battery life).

Apple continues strategy of reducing cost of other components

Apart from the SoC, Apple continues to emphasize profit margins by keeping cost down on several of the other hardware components, especially memory size, with some of its technical specifications already for some time having been superseeded in competitive high-end devices.

Cost-reducing features include limiting DRAM to 1GB (which can have performance repercussions for common uses cases) and internal flash storage to 16GB for the standard models (which will be the primary sellers), a mature LTE modem chip that does not support the latest LTE Cat 6 speeds, a rear-mounted mono speaker and a 8MP camera (although with most likely good performance due to relatively large sensor pixel size).

Source: AnandTech (iPhone 6 announcement), Wikipedia (iPhone 6 article), Wikipedia (Apple A8 article), MacRumors, iFixit, ChipWorks (Apple A8 analysis), AnandTech (Discussion of ChipsWorks analysis), AnandTech (iPhone 6 review)

Updated October 2, 2014 (Add SoC details from recent full AnandTech review, discussion of impact of memory subsystem synthetic benchmarks).
Updated October 20, 2014 (Add comment about potential use of L3 cache for framebuffer memory).