Use FP32 to do the calculations while dequantizing to improve existing Q8_0 quants and to avoid double dtype conversion. Add Q4_1 and Q5_1 dequant kernels
ComfyUI-GGUF
GGUF Quantization support for native ComfyUI models
This is currently very much WIP. These custom nodes provide support for model files stored in the GGUF format popularized by llama.cpp.
While quantization wasn't feasible for regular UNET models (conv2d), transformer/DiT models such as flux seem less affected by quantization. This allows running it in much lower bits per weight variable bitrate quants on low-end GPUs.
Installation
Important
Make sure your ComfyUI is on a recent-enough version to support custom ops when loading the UNET-only.
To install the custom node normally, git clone this repository and install the only dependency for inference (pip install --upgrade gguf)
git clone https://github.com/city96/ComfyUI-GGUF
To install the custom node on standalone, open a CMD inside the "ComfyUI_windows_portable" folder (where your run_nvidia_gpu.bat file is) and use the following commands:
git clone https://github.com/city96/ComfyUI-GGUF ComfyUI/custom_nodes/ComfyUI-GGUF
.\python_embeded\python.exe -s -m pip install -r .\ComfyUI\custom_nodes\ComfyUI-GGUF\requirements.txt
Usage
Simply use the GGUF Unet loader found under the bootleg category. Place the .gguf model files in your ComfyUI/models/unet folder.
Pre-quantized models:
Warning
LoRA / Controlnet / etc are currently not supported due to the weights being quantized.