It was so slow to run an x86 ubuntu os on an apple arm that it was unusuable. I switched to running an arm ubuntu on apple arm, that was fast.

No, it will use Rosetta 2, which uses a combination of JIT and AOT to do binary translation, which is actually quite fast.

No, it will not, it is not supported with windows emulated machines. It will work for linux machines to some degree using the additional binfmt handlers which can call out to rosetta. But that's mostly in user space.

Does Rosetta 2 apply to OS or apps in VMs? I’m not so sure about that.

Only apps in VMs (and only for Linux x86-64 guests at that), unfortunately.

Here’s Apple’s documentation on the mechanism: https://developer.apple.com/documentation/virtualization/run...