Contrary to earlier published reports, the iPhone’s A6 chip is not the first ARM Cortex A15 processor in public usage. According to AnandTech, it is something entirely different and perhaps more significant: a CPU core of Apple’s own design.
It turns out I was wrong. But pleasantly surprised.
The A6 is the first Apple SoC to use its own ARMv7 based processor design. The CPU core(s) aren’t based on a vanilla A9 or A15 design from ARM IP, but instead are something of Apple’s own creation.
To be clear, the A6 is still based off ARM’s designs. It is not an ARM-specific CPU design like a Cortex A8, A9, or a new A15. What does this mean?
The short version is that this allows Apple to customize the chip’s performance to Apple’s needs rather than pushing it or pulling it into ARM’s designs. (Anand takes us through a longer version.)
Qualcomm has done the same thing with its Snapdragon processors, as have others, but this is the first time Apple has gone away from a standard CPU processor design. Interestingly, Samsung’s Exynos processors, which are fabbed at the same company as Apple’s A6’s (and therefore often get compared), are standard ARM designs.
Anandtech also postulated that Apple used a slightly upclocked PowerVR SGX 543MP3 GPU on the SoC to achieve the 2x graphics stat. However, Apple often underclocks higher-end processors depending on usage profile.