Apple Rolls Its Own Dual Core A6 For The iPhone 5
Of course, Apple's much anticipated iPhone 5 made a big splash (see Apple Announces iPhone 5: Big Surprise!). It brings 4G support to the iPhone moving it on par with the flood of Android phones. Among the changes in the iPhone 5 is the move to the 1.3 GHz Apple A6 SoC (Fig. 1) from the Apple A5 found in the earlier iPhones.
Figure 1. Apple's A6 is a dual core Arm-based SoC with three GPU cores based on iFixit's teardown of the chip.
Apple is not the most open company when it comes to revealing their underlying technology. It is why I usually turn to iFixit that regularly tears down the latest electronic gadgets like the Google's Nexus 7 tablet (see iFixit Tears Down The Google Nexus 7 Tablet). Their iPhone 5 teardown is typical but they went the extra yard with the Apple A6 teardown. The process iFixit used to examine the A6 is a story in itself. They used a range of new tools in their lab for analyzing chips and other tiny (microscopic) tech toys.
Apple's A6 is as unique as its A5 so direct comparisons with other platforms like Texas Instrument's OMAP series or NVidia's Tegra series that are based on Arm's Cortex-A9 architecture. iFixit indicates that the A6 uses Arm's armv7s architecture. The main difference between the armv7, used with the Cortex-A9, and armv7s architecture is support for the VFPv4 floating point instructions. The armv7s architecture is used by Arm's Cortex-A15 MPCore (see Arm Delivers More Multicore Multimedia) as well as Qualcomm's Krait SoC. Apple and Qualcomm are allowed to design their own cores. The armv7s architecture is also used with the Cortex-A5 and Cortex-A7 (see Little Core Shares Big Core Architecture).
So is the A6 an enhanced Cortex-A9 or a Cortex-A15? Given the size it is likely something in between but closer to a Cortex-A15. The Cortex-A15 is about 40% faster than the Cortex-A9 an Apple has tuned its A6 based on its layout. Apple designers also incorporated advanced power management and the layout is likely to have made use of extensive clock gating as well as other techniques to reduced the amount of power required to run the A6.
The Apple A6 also squeezes in three GPU cores versus four in the A5. Still, the A6 is likely to run rings around the A5 given its faster clock and new architecture on the GPU as well as CPU sides. Overall, the iPhone 5 is faster in all areas including graphics compared to the iPhone 4s.
At this point I can only speculate whether Apple tweaked the design to give its iOS operating system additional advantages. I would assume this is the case given Apple's ability to tune both the hardware software. No other vendor has this ability.
The A6 chip is manufactured by Samsung. It uses Samsung's 32 nm High-k metal gate (HKMG) process. The chip is 22% smaller than the A5 at 96.71 mm2. It is more powerful but consumes less power.
If the trends hold true then Apple's A6 is likely to show up in the next Apple iPad. The current incarnation employs the A5.