Apple A9 / PowerVR GT7600 vs Apple A9X / PowerVR Series 7XT

Apple A9 / PowerVR GT7600

The PowerVR GT7600 from Imagination Technologies is a high-end smartphone GPU as part of the Apple A9 SoC for the iPhone 6s and 6s Plus. At the time of announcement on September 2015, it is the fastest GPU for smartphones and even bests current tablet GPUs.

Architecture

The GT7600 is part of the Series 7XT line-up and is based on a unified shader architecture with 6 clusters that integrate 384 (FP16) and 192 (FP32) ALU cores. Compared to the Series 6XT GPU in the Apple A8 and A8x, ImgTec states that the performance and efficiency of the cores have been improved. Furthermore, the GPU features support for virtualization, hardware-based security, geometry shaders, tessellation, native 10-bit YUV and ASTC LDR/HDR. DirectX 11 and OpenCL FP64 are optional features that are likely not implemented on Apple smartphones and tablets.

Performance

The PowerVR GT7600 is clearly the fastest smartphone GPU on the market as of September 2015. In all of our benchmarks, the GPU is able to beat even the fastest tablet and smartphone GPUs like the PowerVR GXA6850 in the A8x (iPad Air 2), Tegra K1 (Nvidia Shield Tablet) and Adreno 430 (various flagship smartphones). The ARM Mali-T760 MP8 (7420 Octa) in the Galaxy S6 line-up is also no match for the PowerVR GPU. 

The Tegra X1 in the Shield TV console is able to beat the GT7600 in 3DMark 2013 Unlimited GPU (135%), but falls behind in GFXBench 3.0 Manhattan with 79% of the performance. Thanks to the efficient use of the GPU (e.g., IOS apps using Metal), we are expecting a graphical step up in 3D games.

Power Consumption

The PowerVR GT7600 in the Apple A9 should be very energy efficient due in part to the use of 3D transistors and an improved 14/16 nm fabrication process.

Note: The PowerVR GT7600 in the Apple A9 is not officially confirmed by Apple!

Apple A9X / PowerVR Series 7XT

The Apple A9X / PowerVR Series 7XT GPU is an integrated graphics card in the Apple A9X SoC which can be found in the 2015 Apple iPad Pro. At the End of 2015 it is one of the fastest GPU in ARM based tablets (next to the Nvidia Tegra X1).

According to Chipworks, the GPU offers 12 shader clusters (384 ALUs) and therefore twice as many as the A9 (6 clusters, 192 ALUs) in the iPhone 6S. Currently there is no marketing name for the 12 shader version and it seems to be a custom variant for Apple. It is manufactured in 14/16 nm (3D transistors) at TSMC and Samsung (according to rumors).

The performance of the GPU is very good and in GFXBench the results are even better than a current GeForce 940M laptop graphics card. However, the direct comparisons of different platforms should only give a rough indication on the speed. Thanks to the Metal API, the iPad is able to use the graphics hardware very efficiently.