The new, new iPad comes with yet another system-on-chip called the A6X which is a dual-core and has a quad-core GPU. What we already know is that the A6X has twice the CPU performance as the A5X which, itself is twice as powerful as the A5. We do know what the latter is based on the Cortex-A9. As for the A6, which powers the iPhone 5, it is “up to twice” the performance of the CPU and graphics performance of the A5.
So, in clearer terms, as far as CPU performance is concerned, the A5 represents one unit, the A5X and the A6 represent two units and the A6x four units. As for GPU performance, the A5 is one unit, the A5X and the A6 is two units and the A6x, four units.
Until we have a proper analysis of the SoC’s silicon, the most likely theory is that Apple adopted the same CPU cores as on the A6 and possibly pushed up the processor speed, while switching to a lower manufacturing node (the A6 is built on a 32nm process), something that would make sense given that the battery life appears to be more or less constant.
Apple also added one more GPU core to the A6, swapping the PowerVR SGX 543MP4 for something beefier. At equal speed, each core must be at least twice as powerful as the SGX543 which means that whatever is in the iPad 4 could be the first Series 6 Power VR Rogue GPU.