The iPhone 5 Performance Preview

This morning we finally got our hands on Apple's iPhone 5. While we are eager to get started on battery life testing, that'll happen late tonight after a full day's worth of use and a recharge cycle. Meanwhile, we went straight to work on performance testing. As we've mentioned before, the A6 SoC makes use of a pair of Apple's own CPU cores that implement the ARMv7 ISA. These aren't vanilla Cortex A9s or Cortex A15s, but rather something of Apple's own design. For its GPU Apple integrated a PowerVR SGX543MP3 GPU running at higher clocks than the dual-core 543MP2 in the A5. The result is compute performance that's similar to the A5X in Apple's 3rd generation iPad, but with a smaller overall die area. The A6 has a narrower memory interface compared to the A5x (64-bits vs. 128-bits), but that makes sense given the much lower display resolution (0.7MP vs. 3.1MP).

As always, our performance analysis starts out on the CPU. Although we originally thought the A6 ran its two CPU cores at 1GHz, it looks like max clocks range between 800MHz and 1.2GHz depending on load. Geekbench reports clock speed at launch, which varied depending on CPU load. With an app download process in the background I got Geekbench to report a 1.2GHz clock speed, and with everything quiet in the background the A6 reported 800MHz after being queried. This isn't anything new as dynamic voltage/frequency adjustment is in all smartphones, but we do now have a better idea of the range.

http://www.anandtech.com/show/6324/the-iphone-5-performance-preview