* https://www.tomshardware.com/news/amd-ryzen-hackintosh-syste...
* https://www.tomshardware.com/news/amd-ryzen-hackintosh-syste...
x86 is not an open ISA. For all practical purposes nobody besides intel and AMD can make x86 chips.
Pretty much anybody can ask ARM to get a license to make ARM chip.
Sure Macs have special chips in addition but that is true for their intel offerings as well. You have never been able to just plop an AMD chip into a Mac so it is not like that choice ever meant anything to consumers.
The ARM ISA versus x86 ISA is probably the least complicated part of this equation. At least on x86 there were widely used graphics components that were leveraged. What exactly do we know about the built-in GPU on the M1?
(there's technically nothing preventing you of running macOS arm64 on non-Apple hardware in a VM)
It's because if the GPU is reverse engineered enough, you can simulate an Apple GPU on another machine _and_ run other OSes with a proper GPU stack on those macs.
Now I don’t know anything about GPU stacks, but I could imagine that one change essentially requiring a rewrite of the entire stack if certain assumptions were baked into the old one.
The new model would seem to allow the developer to allocate a buffer full of stuff and rapidly alternate between CPU and GPU instructions on that buffer, without copying. If so, that’s a pretty huge win for performance.
Currently, Apple and NVIDIA have the beefiest UMA w/ the CPU GPUs available, and those are Arm solutions.
Most vendors of graphics hardware keep their interface secret, but not all. The problem is that the set of hardware that isn't secret won't overlap much with what people have or want to run, which is pretty central to what makes Hackintoshes attractive.