PixArt Sigma 900M: Enhanced Text-to-Image Model

Model Overview

PixArt Sigma 900M is a text-to-image generation model based on the PixArt Sigma architecture. This version has been expanded to 900M parameters, up from the original 600M base model. Two distinct variants are available:

1. PixArt Sigma 900M Base (Photorealistic)

2. PixArt Sigma 900M Anime

Key Features

• 900M parameters (300M more than the base model)

• Improved image generation quality

Technical Details

• Architecture: PixArt Sigma variant

• Parameter Count: 900 million

• Base Model: 600M PixArt Sigma

Credits

• Original PixArt Sigma model by PIXART-Σ (pixart-alpha.github.io)

• Based on jimmycarter (Jimmy Carter) (huggingface.co) adaptation of PixArt Sigma

ComfyUI Compatibility

To use this model in ComfyUI, a custom node is required as ComfyUI does not natively support this variant at the moment. The necessary custom node can be found at: https://github.com/city96/ComfyUI_ExtraModels

Required Components

1. T5 Model:

   • Download from: PixArt-alpha/PixArt-Sigma-XL-2-1024-MS at main (huggingface.co) on Hugging Face

   • Naming Convention: Ensure the T5 model files are named exactly as they appear in the repository

   • Important: Remove any prepended "text_encoder" from the filenames if present

Setup Instructions

1. Download the T5 model from the Hugging Face repository linked above

2. Rename the T5 model files if necessary, removing any "text_encoder" prefix

3. Install the custom ComfyUI node from the GitHub repository

4. Place all model files in the appropriate directories as specified in the ComfyUI_ExtraModels documentation