The Apple A8X is a 64-bitsystem on a chip (SoC) designed by Apple Inc. and manufactured by TSMC.[1] It first appeared in the iPad Air 2, which was announced on October 16, 2014.[6] It is a variant of the A8 inside the iPhone 6 family cellphones and Apple states that it has 40% more CPU performance and 2.5 times the graphics performance of its predecessor, the Apple A7.[6][7]
The A8X has three cores clocked at 1.5 GHz, a more powerful GPU compared to the A8 and it contains 3 billion transistors.[7] With the extra 100 MHz, it performs around 13% better on single threaded and 55% better on multithreaded operations than the A8 inside the iPhone 6 and 6 Plus.[2]
Further comparison to the A8 shows that the A8X uses a metal heat spreader, which the A8 does not, and it doesn't use the package on package configuration with included RAM which the A8 does. This is similar to how the older "X" variants, the A5X and A6X, were designed.[8] Instead the A8X in the iPad Air 2 uses an external 2 GB RAM module.[2][8]