[Feature] Optimal use of Metal backend #1330
Description
Feature Summary
Explain Metal backend status, with guidelines.
Detailed Description
I feel it strange that the prebuilt releases have Metal disabled, but after reading open issues about Metal crashes or too slow performance, I'm guessing that maybe you are disabling it on official builds because it's not ready for normal use.
If the Metal backend is well tested and some developers use it, there should be documentation explaining how to set it up and recommended ways of using it for optimal performance. On the other hand, if it's not in working status yet, I think you should add some notice about that, so that other users don't take the effort of building it if it's not going to work.
But I suggest that you keep the backend even if it's not ready yet, because the alternatives (Mochi Diffusion, DiffusionBee, or the open source Apple stable diffusion implementation) are not so powerful as stable-diffusion.cpp, and it would be great to have it working on Metal. I have a M4 Max and I'd really like to have it optimally working on my machine.
Alternatives you considered
No response
Additional context
No response