So here's a bonus for all of you: the A5X cover removed.

Underneath the cover we find the A5X processor flip chip mounted onto the carrier PWB.

It's a safe bet that the A5X cover is a heat sink for the CPU, given there's thermal paste underneath and a thermal pad on top of the cover.

The A5X measures 12.82 mm x 12.71 mm (162 mm^2) which is 36% larger than the A5.