I'm on a iMac M1 16gb and I can handle up to 768x768 but since it's shared memory I close out every other application and run things overnight.
The biggest issue with apple chips is that the --seed setting doesn't work. I should be able to set a seed to, for instance, 1083958 and if I re-run a command at the same resolution with that seed, I should get the same image every time. This would allow me to test different steps so I could generate a 100 images at 16 steps (which is quite fast) and pick the ones that are most promising and re-render at 64 or 128 steps.
But currently you can't do that on apple hardware because of an open issue in PyTorch. Genuinely hoping a fix comes soon, until it is this is more of a novelty than a tool on Apple hardware.
Me at the end of last year: "Should I really go for the full 64GB on this M1 Pro? What could I possibly use this for? mmbml mumble... something about unified GPU... something Deep Learning, one day..."
Me now: "a red juicy apple floating in outer space, like a planet" --H 768 --W 768
I was so geniunely happy with my 16GB iMac M1 until stable-diffusion released.
I was amazed at how fast and powerful it was. I thought this meant I could stop buying top-of-the-line Macs every 4 years and start buying bottom-of-the-line Macs every 5 years. And that would have been 100% true... if it weren't for stable-diffusion.
It seems the GPU memory requirements beyond 512x512 are obscene.