Apple Using Semi-Custom 8 Core GPU in iPad Air 2
Anandtech did some digging and discovered that the GPU in the iPad Air 2 is a customized 8-core design, rather than the 6 core generally assumed.
Ryan Smith at Anandtech says:
Since publishing our initial iPad Air 2 review last week, a few new pieces of information have come in that have changed our perspective on Appleâs latest SoC. As it turns out I was wrong. Powered by what weâre going to call the GXA6850, the A8Xâs GPU is even better than I thought.
[…] By drawing outside of the lines and building an eight cluster GPU configuration where none previously existed, the A8X and its GXA6850 GPU are more powerful than even we first suspected. Apple traditionally aims high with its SoCs, but this ended up being higher still.
In a nutshell, the A8X features two of the GPUs used by the standard A8 chip in the iPhone 6 and iPhone 6 Plus. Putting it another way, it features two GPUs that are noticeably better than the one GPU used in the first iPad Air, and all iPad Minis.
The screen on the iPad is about 3 megapixels, compared with 2 megapixels on the iPhone 6 Plus and 1 megapixel on the standard iPhone 6. This creates an interesting situation where games running at full resolution on the iPad Air 2 perform about 50% better than on the iPhone 6 Plus and about 50% worse than on the regular iPhone 6; I’ve gone into detail about how and why this is before, and will continue to examine gaming performance on Apple’s devices.