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.
These are still narrowly focused tests, we'll be doing some more holisitic browser tests over the coming days. Finally we have Geekbench 2, comparing the iPhone 5 and 4S:
|Geekbench 2 Performance|
|Geekbench 2 Overall Scores||Apple iPhone 4S||Apple iPhone 5|
A6 GPU Performance: Nearly Identical to the iPad 3Before we got a die shot of Apple's A6 we had good information pointing to a three core PowerVR SGX 543MP3 in the new design. As a recap, Imagination Technologies' PowerVR SGX543 GPU core features four USSE2 pipes. Each pipe has a 4-way vector ALU that can crank out 4 multiply-adds per clock, which works out to be 16 MADs per clock or 32 FLOPS. Imagination lets the customer stick multiple 543 cores together, which scales compute performance linearly. The A5 featured a two core design, running at approximately 200MHz based on our latest news. The A5X in the 3rd generation iPad featured a four core design, running at the same 200MHz clock speed.
The A6 on the other hand features a three core PowerVR SGX 543MP3, running at higher clock speeds to deliver a good balance of die size while still delivering on Apple's 2x GPU performance claim. The raw specs are below:
|Mobile SoC GPU Comparison|
|Adreno 225||PowerVR SGX 540||PowerVR SGX 543MP2||PowerVR SGX 543MP3||PowerVR SGX 543MP4||Mali-400 MP4||Tegra 3|
|# of SIMDs||8||4||8||12||16||4 + 1||12|
|MADs per SIMD||4||2||4||4||4||4 / 2||1|
|GFLOPS @ 200MHz||12.8 GFLOPS||3.2 GFLOPS||12.8 GFLOPS||19.2 GFLOPS||25.6 GFLOPS||7.2 GFLOPS||4.8 GFLOPS|
|GFLOPS As Shipped by Apple/ASUS||-||-||12.8 GFLOPS||25.5 GFLOPS||25.6 GFLOPS||-||12
We ran through the full GLBenchmark 2.5 suite to get a good idea of GPU performance. Note that the 3rd gen iPad results are still on iOS 5.1 so there's a chance you'll see some numbers change as we move to iOS 6.
We'll start out with the raw theoretical numbers beginning with fill rate:
Once again, looking at GLBenchmark's on-screen and offscreen Egypt tests we can get a good idea of how the iPhone 5 measures up to Apple's claims of 2x the GPU performance of the iPhone 4S: