Today’s report from Mark Gurman, Debby Wu, and Ian King at Bloomberg builds upon a 2018 Bloomberg story: Apple is working on Macs and a version of MacOS running on ARM processors of its own design, and it aims to release the first one next year.
That’s all fascinating, but this report fails to answer what is perhaps the most obvious question about ARM-powered Macs:
Despite a unified chip design, Macs will still run the macOS operating system, rather than the iOS software of the iPhone and iPad. Apple is exploring tools that will ensure apps developed for older Intel-based Macs still work on the new machines. The company also has technology called Catalyst that lets software developers build an iPad app and run it on Mac computers.
Moving macOS from Intel’s chip architecture to an Arm-based design will be a technical challenge. Microsoft Corp. stumbled with a similar effort.
Ignore the Catalyst red herring. Catalyst apps have been running on Intel since MacOS Mojave, and no report that I have seen — including this one — indicates that it is related to this processor transition. Instead, let’s focus on the overall concept of running MacOS on ARM.
When Apple transitioned the Mac from PowerPC to Intel processors around fourteen years ago,1 it added a feature to Mac OS X called Rosetta which translated most typical binaries across system architectures. Some applications ran fine, but most were kind of slow, and a few specific categories of PowerPC code did not run at all through Rosetta.
For its part, Microsoft has been shipping Windows 10 for x86 — Intel and AMD — and ARM architectures since 2017. There is an x86-to-ARM translator built into the system, but it faces similar limitations; perhaps most notably, it is so far incapable of running 64-bit applications, which is kind of necessary for MacOS.
It is perhaps foolish of me to say that I expect an ARM-based Mac to feature some kind of Intel translator or emulator, but I would be shocked if it did not. There are over 100 million active Mac users out there compared to 36 million in 2008, a number that was surely even lower when Apple announced the Intel switch in 2005. Yet, this report sheds no light on that critical mystery, and I am aching to find out.
Also, for what it’s worth, the Mac has now run on Intel for a few years longer than it did on PowerPC. ↩︎