Maple Diffusion runs Stable Diffusion models locally on macOS / iOS devices, in Swift, using the MPSGraph framework (not Python).
Maple Diffusion should be capable of generating a reasonable image in a minute or two on a recent iPhone (I get around ~2.3s / step on an iPhone 13 Pro).
To attain usable performance without tripping over iOS's 4GB memory limit, Maple Diffusion relies internally on FP16 (NHWC) tensors, operator fusion from MPSGraph, and a truly pitiable degree of swapping models to device storage.
On macOS, Maple Diffusion uses slightly more memory (~6GB), to reach <1s / step.
Projects using Maple Diffusion
- https://github.com/mortenjust/maple-diffusion/ is a fork with several improvements
Maple Diffusion should run on any Apple Silicon Mac (M1, M2, etc.). Intel macs seem to not support Float16 or something.
Maple Diffusion should run on any iOS device with sufficient RAM (≥6144MB RAM definitely works; 4096MB might but I wouldn't bet on it; anything lower than that won't work). Recent iPads should work out of the box; recent iPhones should work if you can get the
Increase Memory Limit capability working (to unlock 4GB of RAM).
iOS 16.1 (beta) is reportedly broken and always generating a gray image :(
To build and run Maple Diffusion:
Download a Stable Diffusion PyTorch model checkpoint (
sd-v1-4.ckpt, or some derivation thereof)
Download this repo
git clone https://github.com/madebyollin/maple-diffusion.git && cd maple-diffusion
Setup & install Python with PyTorch, if you haven't already.
# may need to install conda first https://github.com/conda-forge/miniforge#homebrew conda deactivate conda remove -n maple-diffusion --all conda create -n maple-diffusion python=3.10 conda activate maple-diffusion pip install torch typing_extensions numpy Pillow requests pytorch_lightning
Convert the PyTorch model checkpoint into a bunch of fp16 binary blobs.
maple-diffusionXcode project. Select the device you want to run on from the
Product > Destinationmenu.
Manually add the
Increased Memory Limitcapability to the
maple-diffusiontarget (this step might not be needed on iPads, but it's definitely needed on iPhones - the default limit is 3GB).
Build & run the project on your device with the
Product > Runmenu.