Using LCM

LCM: Latent Consistency Model

LCM (Latent Consistency Model) is a new feature that provides support for SD 1.5 and SD-XL models.

Installation

Download the LCM LoRA models and place them in your LoRA folder (models/lora or custom):

• For SD 1.5: lcm-lora-sdv1-5
• For SD-XL: lcm-lora-sdxl

As they have the same name, we recommend doing them one at a time and then renaming it before downloading the next.

Usage

1. Make sure to use the Diffusers backend in SDNext, Original backend will NOT WORK
2. Load your preferred SD 1.5 or SD-XL model that you want to use LCM with
3. Load the correct LCM lora (lcm-lora-sdv1-5 or lcm-lora-sdxl) into your prompt, ex: <lora:lcm-lora-sdv1-5:1>
4. Set your sampler to LCM
5. Set number of steps to a low number, e.g. 4-6 steps for SD 1.5, 2-8 steps for SD-XL
6. Set your CFG Scale to 1 or 2 (or somewhere between, play with it for best quality)
7. Optionally, turning on Hypertile and/or FreeU will greatly increase speed and quality of output images
8. ???
9. Generate!

Notes

• This also works with latent upscaling, as a second pass/hires fix.
• LCM scheduler does not support steps higher than 50
• The cli/lcm-convert.py script can convert any SD 1.5 or SD-XL model to an LCM model by baking in the LoRA and uploading to Huggingface