http://www.anandtech.com/show/9766/the-apple-ipad-pro-review/2Oh gotcha, you might need to revise a bit then. If I remember correctly the A8 (or the A8X) is already a 128 bus device, meaning the A9 is as well. I need to reread the Ars articles......
A8X 128-bit DDR3
A9 64-bit DDR4
A9X 128-bit DDR4