CUDA

NixOS supports using NVIDIA GPUs for pure computing purposes, not just for graphics. For example, many users rely on NixOS for machine learning both locally and on cloud instances. These use cases are supported by the @NixOS/cuda-maintainers team on GitHub. If you have an issue using your NVIDIA GPU for computing purposes open an issue on GitHub and tag @NixOS/cuda-maintainers.

Tip

Cache: Using the cuda-maintainers cache is recommended! It will save you valuable time and electrons. Getting set up should be as simple as cachix use cuda-maintainers. Click here for more details.

Tip

Data center GPUs: Note that you may need to adjust your driver version to use "data center" GPUs like V100/A100s. See this thread for more info.

cudatoolkit, cudnn, and related packages

The CUDA toolkit is available in a number of different versions. Please use the latest major version. You can see where they're defined in nixpkgs here.

Several "CUDA-X" libraries are packages as well. In particular,

• cuDNN is packaged here.
• cuTENSOR is packaged here.

Warning: Note that these examples haven't been updated in a while (as of 2022-03-12). May not be the best solution. A better resource is likely the packaging CUDA sample code here.

There are some possible ways to setup a development environment using CUDA on NixOS. This can be accomplished in the following ways:

• By making a FHS user env

cuda-fhs.nix

# Run with `nix-shell cuda-fhs.nix`
{ pkgs ? import <nixpkgs> {} }:
(pkgs.buildFHSUserEnv {
  name = "cuda-env";
  targetPkgs = pkgs: with pkgs; [ 
    git
    gitRepo
    gnupg
    autoconf
    curl
    procps
    gnumake
    util-linux
    m4
    gperf
    unzip
    cudatoolkit
    linuxPackages.nvidia_x11
    libGLU libGL
    xorg.libXi xorg.libXmu freeglut
    xorg.libXext xorg.libX11 xorg.libXv xorg.libXrandr zlib 
    ncurses5
    stdenv.cc
    binutils
  ];
  multiPkgs = pkgs: with pkgs; [ zlib ];
  runScript = "bash";
  profile = ''
    export CUDA_PATH=${pkgs.cudatoolkit}
    # export LD_LIBRARY_PATH=${pkgs.linuxPackages.nvidia_x11}/lib
    export EXTRA_LDFLAGS="-L/lib -L${pkgs.linuxPackages.nvidia_x11}/lib"
    export EXTRA_CCFLAGS="-I/usr/include"
  '';
}).env

• By making a nix-shell

cuda-shell.nix

# Run with `nix-shell cuda-shell.nix`
{ pkgs ? import <nixpkgs> {} }:
pkgs.mkShell {
   name = "cuda-env-shell";
   buildInputs = with pkgs; [
     git gitRepo gnupg autoconf curl
     procps gnumake util-linux m4 gperf unzip
     cudatoolkit linuxPackages.nvidia_x11
     libGLU libGL
     xorg.libXi xorg.libXmu freeglut
     xorg.libXext xorg.libX11 xorg.libXv xorg.libXrandr zlib 
     ncurses5 stdenv.cc binutils
   ];
   shellHook = ''
      export CUDA_PATH=${pkgs.cudatoolkit}
      # export LD_LIBRARY_PATH=${pkgs.linuxPackages.nvidia_x11}/lib:${pkgs.ncurses5}/lib
      export EXTRA_LDFLAGS="-L/lib -L${pkgs.linuxPackages.nvidia_x11}/lib"
      export EXTRA_CCFLAGS="-I/usr/include"
   '';          
}

Setting up CUDA Binary Cache

The cuda-maintainers cache contains pre-built CUDA packages. By adding it to your system, Nix will fetch these packages instead of building them, saving valuable time and processing power.

For more information, refer to the Using a binary cache page.

Warning: You need to rebuild your system at least once after adding the cache, before it can be used.

NixOS

Add the cache to substituters and trusted-public-keys inside your system configuration:

/etc/nixos/configuration.nix

nix.settings = {
  substituters = [
    "https://cuda-maintainers.cachix.org"
  ];
  trusted-public-keys = [
    "cuda-maintainers.cachix.org-1:0dq3bujKpuEPMCX6U4WylrUDZ9JyUG0VpVZa7CNfq5E="
  ];
};

Non-NixOS

If you have cachix installed and set up, all you need to do is run:

$ cachix use cuda-maintainers

Else, you have to add substituters and trusted-public-keys to /etc/nix/nix.conf:

/etc/nix/nix.conf

trusted-public-keys = cuda-maintainers.cachix.org-1:0dq3bujKpuEPMCX6U4WylrUDZ9JyUG0VpVZa7CNfq5E=
trusted-substituters = https://cuda-maintainers.cachix.org
trusted-users = root @wheel

If your user is in trusted-users, you can also add the cache in your home directory:

~/.config/nix/nix.conf

substituters = https://cuda-maintainers.cachix.org

Some things to keep in mind when setting up CUDA in NixOS

• Some GPUs, like Tesla K80, don't work with the latest drivers, so you must specify them in the option hardware.nvidia.package getting the value from your selected kernel, for example, config.boot.kernelPackages.nvidia_x11_legacy470. You can check which driver version your GPU supports by visiting the nvidia site and checking the driver version.
• Even with the drivers correctly installed, some software, like Blender, may not see the CUDA GPU. Make sure your system configuration has the option hardware.opengl.enable enabled.
• By default, software packaged in source code form has CUDA support disabled, because of the unfree license. To solve this, you can enable builds with CUDA support with a nixpkgs wide configuration, or use binary packaged CUDA compatible software such as blender-bin.

CUDA under WSL

This (surprisingly) works just fine using nixpkgs 23.05 provided that you prefix the LD_LIBRARY_PATH in your interactive environment with the WSL library directory. For nix shell this looks like:

cuda-shell.nix

   shellHook = ''
      export CUDA_PATH=${pkgs.cudatoolkit}
      export LD_LIBRARY_PATH=/usr/lib/wsl/lib:${pkgs.linuxPackages.nvidia_x11}/lib:${pkgs.ncurses5}/lib
      export EXTRA_LDFLAGS="-L/lib -L${pkgs.linuxPackages.nvidia_x11}/lib"
      export EXTRA_CCFLAGS="-I/usr/include"
   '';

See also

• nixos-cuda-example
• nix-shell envs for Cuda
• CUDA setup on NixOS
• eGPU with nvidia-docker on intel-xserver
• Tesla K80 based CUDA setup with Terraform on GCP