A Bloomberg report that came out yesterday speculated that Arm based Mac’s could come as early as 2020. Given both Apple’s silicon roadmap and its hardware and software roadmap, that timing seems plausible. The bigger question is why would Apple make a change, and more importantly pour so much R&D developing a custom chip for Mac hardware when they still only sell roughly 20 million Macs a year. I think a few key reasons make the most sense.
