Comment from github: "By the way, i confirmed to work on my Intel 16-in MacBook Pro via mps. GPU (Radeon Pro 5500M 8GB) usage is 70-80% and It takes 3 min where --n_samples 1 --n_iter 1. My repo https://github.com/cruller0704/stable-diffusion-intel-mac"
For comparison, my RTX 2070 takes 10 seconds for one image (512x512)
I believe the branch which adds support for Apple Silicon also adds support for running on Intel chips (albeit extremely slowly). I haven't tested it myself, but I've seen several people in the GitHub issues saying this.
The standard release works fine, if you tweak the code to use the CPU pytorch device instead of CUDA. It does take about an hour to generate a set of images with the standard options on my AMD 2600 CPU though!