The first thing to say about the M1 Pro and M1 Max, Apple’s new homegrown processors, is that we misunderestimated them. The chips were a well-guarded secret; pre-announcement scuttlebutt mentioned an “M1X” chip, christened in the manner of the A12X that powers the third generation 2018 iPad Pro. Just as the A12X was a brawny derivative of the A12 found in the 2018 iPhone X series, with an additional core, a beefier GPU (Graphics Processing Unit), dedicated neural network hardware, and 70% more transistors, so, too, the M1X will add a little bit of everything to the well-regarded SoC (System On a Chip).
Link: Apple M1 Pro & Max Surprises. by Jean-Louis Gassée