I recently wrote about the M4 Mac’s compelling lineup and now is a great time to buy a Mac. However, one type of user will want to delay a purchase.
According to Howard Oakley of The Eclectic Light Company, the new M4 Macs will not allow virtual machine software to work properly. Users who want to run versions of macOS earlier than Ventura 13.4 via virtualization will find that the virtual machine will not boot and users will be left with a blank screen. Since the virtual machine (VM) is not starting at all, there is no way to access the log to see what the problem could be.
Oakley reports that Activity Monitor shows that with the VM, only one CPU core is active even if multiple cores are allocated. This could mean that the problem occurs “before the VM kernel boots the other cores, an event that occurs early in the kernel boot phase.” Until then, the pre-boot phases and the kernel run on a single CPU core.
This limitation means that virtual machines on M4 Macs can only run macOS Ventura 13.4 and later. The issue does not affect M1, M2, and M3 Macs, which can run virtual machines with macOS Monterey 12 or later. M-series Macs cannot run virtual machines from macOS Big Sur 11 or earlier. Oakley tried running the VM on a single CPU core, but it still didn’t work on the M4.
The issue has been reported to Apple, but it is unclear whether a fix can or will be available. Oakley suggests that Apple could fix the problem by modifying the kernels of older versions of macOS, but that seems like a task Apple isn’t going to accomplish. So for now, if running older versions of macOS is vital to your workflow, you may want to hold off on a new M4 purchase or at least stick with an older Mac.
