Full Installation Guide for ComfyUI with Python Virtual Environment (venv)

This guide explains how to install ComfyUI in an isolated Python virtual environment with an advanced configuration:

• Python: 3.12.9
• Torch: 2.9.0.dev20250716+cu128
• Triton: triton-windows==3.3.1.post19
• SageAttention: enabled
• fp16 accumulation: enabled via --fast fp16_accumulation

📡 Recommended GPU: NVIDIA GPU compatible with CUDA 12.8 or higher.

💡 AMD / Other GPUs: This guide is only compatible with NVIDIA GPUs supporting CUDA 12.8 or later. It does not cover installation on AMD, Intel, or CPU-only configurations.

While ComfyUI can theoretically run on these alternatives, expect major limitations:

• Very slow performance (especially without GPU)
• Key features (SageAttention, Triton) require CUDA-compatible NVIDIA GPU
• No official support for ROCm (AMD) or DirectML (Intel)

✅ Compatible GPUs:

• NVIDIA GTX 10xx series, RTX 20xx, 30xx, 40xx, 50xx (e.g., GTX 1080, RTX 2060, 3080, 4090, 5080)

🛑 Not supported:

• AMD Radeon (RX 5000/6000/7000)
• Intel Arc / iGPU
• Any non-NVIDIA GPU

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Requirements

✅ Hardware / Software

• CUDA Toolkit 12.8 installed on your system (mandatory for Torch 2.9 + Triton)

  • Download: https://developer.nvidia.com/cuda-12-8-0-download-archive?target_os=Windows

• OS: Windows 10 or 11

• NVIDIA GPU with CUDA 12.8 support

• Up-to-date NVIDIA drivers

• Python 3.12.9 (check “Add Python to PATH”)

  • https://www.python.org/downloads/release/python-3129/

• Git

  • https://git-scm.com/downloads/win

• Visual Studio Build Tools

  • https://visualstudio.microsoft.com/visual-cpp-build-tools/
  • During installation, check: C++ build tools, MSVC v143, Windows 10 SDK, CMake

• Internet access

• Optional: Notepad++ or similar text editor

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⚙️ Automatic Installation (optional)

To save time, you can use the provided batch script to automate installation. It performs:

• Cloning the ComfyUI repository
• Creating and activating a Python 3.12.9 virtual environment
• Installing specific Torch (2.9.0.dev20250716+cu128) and Triton (3.3.1.post19) versions
• Cleaning requirements.txt
• Installing SageAttention and dependencies
• Creating the launch script launch_comfyUI_torch2.9.bat
• Installing ComfyUI-Manager

💡 To use it:

1. Make sure Python 3.12.9, CUDA Toolkit 12.8, and Visual C++ Build Tools are already installed.
2. Download or copy the .bat file and run it using CMD.

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⚙️ Manual Installation (step-by-step)

❌ Do not use PowerShell

Use CMD to avoid .bat or environment issues.

Clone the ComfyUI repository

1. Open CMD (Win + R → type cmd → Enter).
   ❗ Do not close this window until the installation is complete.

2. In your desired install location, run:

git clone https://github.com/comfyanonymous/ComfyUI.git ComfyUI.torch2.9
cd ComfyUI.torch2.9

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Create and activate Python virtual environment

Ensure Python 3.12.9 is properly installed.

py -m venv venv
call venv\Scripts\activate.bat

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Upgrade pip and build tools

python -m pip install --upgrade pip setuptools wheel

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Install PyTorch Nightly (CUDA 12.8)

pip uninstall torch torchvision torchaudio -y
pip install torch==2.9.0.dev20250716+cu128 torchvision torchaudio --index-url https://download.pytorch.org/whl/nightly/cu128

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Install Triton for Windows

pip install triton-windows==3.3.1.post19

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Clean requirements.txt

Open requirements.txt inside ComfyUI.torch2.9 and remove or comment:

# torch
# torchvision
# torchaudio

Then install dependencies:

pip install -r requirements.txt

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Install SageAttention

python -m pip install sageattention

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Create a launch script

Create a launch_comfyUI_torch2.9.bat file in the ComfyUI.torch2.9 folder with this content:

@echo off
call venv\Scripts\activate.bat
python main.py --use-sage-attention --fast fp16_accumulation --preview-method taesd
pause

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Install ComfyUI-Manager (optional)

cd custom_nodes
git clone https://github.com/ltdrdata/ComfyUI-Manager.git
cd ..

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Fix setuptools conflict

⚠️ This step is mandatory: certain setuptools versions conflict with Triton (especially via pkg_resources).

pip uninstall -y setuptools
pip install setuptools==78.1.1

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Run ComfyUI

Launch launch_comfyUI_torch2.9.bat to start ComfyUI. Check the console to confirm that Torch, Triton, and SageAttention load without errors.

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✨ You're now ready to use ComfyUI with full performance!