iPad 4th gen GPU innards revealed

The newest iPad has had its guts revealed once again, showing off not just the pieces we knew about, the A6X processor included, but the GPU and its abilities as well. The folks at AnandTech have gone in for a deep-dive into the A6X as it exists on the iPad 4, showing a brand new PowerVR SGX 554 GPU. The A6X processor retains many elements from the A5X processor the iPad 3 worked with, including the memory controller interface sitting adjacent to the GPU cores instead of the CPU cores, as it was in the A5 and the standard A6 (on the iPhone 5).

The A6X has been revealed to also retain the 128-bit wide memory interface that the A5X worked with, integrating here two of Apple's Swift cores running right up to 1.4GHz right out of the box. The PowerVR SGX 554 GPU living here in the iPad 4 is far and away more advanced than the units used in the iPad 3 or the iPhone 5, doubling the # of SIMDs of the iPad 3's GPU, the PowerVR SGX 543MP4, essentially one generation back.

This new GPU appears to have double the ALU per core that the iPad 3's unit works with (8 Vec4 ALUs per core vs. 4 Vec4) and brings on what Chipwork's analysis suggests is 2 sets of 4 identical sub-cores and one central core. That analysis shows 9 sub-cores, that is, as shown below, again from Chipworks. Anand suggests that this architecture points toward a theoretical performance greater than 77 GFLOPS – hot stuff!

You'll find in benchmarks galore that this iPad – surprise – beats the older iPad models by a significant margin regardless of the test. The GPU appears to be clocking at least 15% higher than the iPad 3's greatest hits, while tests like GLBenchmark are showing 65% benchmark performance improvement in some cases – in other words: really, really good. Have a peek at our full iPad 4th gen review for more everyday testing and sweet daily action.