M5 PRO AND M5 MAX ARE SURPRISINGLY BIG DEPARTURES FROM OLDER APPLE SILICON

Summary from the TLDR newsletter

Apple's Pro and Max chips usually take the same basic building blocks from the basic chip and just scale them up. However, the M5 Pro and Max chips use a different CPU architecture. The new Fusion Architecture welds two silicon chiplets into a single processor. Rather than just a pair of M5 chips welded together, Apple has one chiplet handle the CPU and most of the I/O, while the other chiplet is used mainly for graphics. Apple is also introducing a new type of 'performance core' that prioritizes multi-threaded performance.