FLASH ATTENTION 2.8.3 FOR RTX 5090 (WINDOWS)
YOU ONLY WANT THIS IF You only need this specific Flash Attention 2.8.3 wheel if you are running an NVIDIA RTX 5090 Blackwell GPU on Windows with CUDA 13 and PyTorch Nightly on Python 3.12, because official installers do not yet exist for this exact hardware and software combination.
INSTALLATION INSTRUCTIONS
Step 1: Download the File Click the Files and versions tab on this page and download the file named: flash_attn-2.8.3+cu130torch2.11-cp312-cp312-win_amd64.whl
Step 2: Prepare Your Environment Open your command prompt or terminal. Make sure you are using the specific Python environment where you want Flash Attention installed. For ComfyUI users, this is usually your python_embeded directory.
Step 3: Install the Wheel Run the following command, making sure to replace path_to_file with the actual location where you downloaded the file.
pip install [path_to_file]\flash_attn-2.8.3+cu130torch2.11-cp312-cp312-win_amd64.whl
Step 4: Verify Installation To confirm it is working, run this quick Python command:
python -c "import flash_attn; print('Success')"
If it prints Success, you are ready to use the library.
TROUBLESHOOTING If you see an error saying the wheel is not supported on this platform, you are likely using the wrong version of Python (must be 3.12) or the wrong version of PyTorch (must be 2.11 Nightly). This file is strictly locked to those versions to ensure stability on the RTX 5090.