Nvidia

Installing Nvidia Drivers on NixOS

NixOS uses a functional package management approach, which necessitates specific procedures for driver installation. When considering NVIDIA GPU drivers in a Linux environment, the installation process can be more complex compared to AMD and Intel. This complexity arises primarily because NVIDIA's official drivers are closed source and not typically bundled with many distributions. This document outlines the technical steps required to install NVIDIA GPU drivers on NixOS, factoring in both the unique nature of NixOS and the proprietary status of NVIDIA's drivers.

Enable Unfree Software Repositories

Make sure to allow Unfree Software. The unfree NVIDIA packages include nvidia-x11, nvidia-settings, and nvidia-persistenced.

Determining the Correct Driver Version

You will next need to determine the appropriate driver version for your card. The following options are available:

hardware.nvidia.package = config.boot.kernelPackages.nvidiaPackages.stable
hardware.nvidia.package = config.boot.kernelPackages.nvidiaPackages.beta
hardware.nvidia.package = config.boot.kernelPackages.nvidiaPackages.vulkan_beta
hardware.nvidia.package = config.boot.kernelPackages.nvidiaPackages.legacy_390
hardware.nvidia.package = config.boot.kernelPackages.nvidiaPackages.legacy_340

Out of the above, `stable` and `beta` will work for the latest RTX cards and some lower cards so long as they're not considered "legacy" by Nvidia. For "legacy" cards, you can consult the Nvidia official legacy driver list and check whether your device is supported by the 390 or 340 branches. If so, you can use the corresponding legacy_390 or legacy_340 driver.

Once you've determined the correct driver version, note it down; you'll need it in the next step.

Modifying NixOS Configuration

Ensure that the following is in your NixOS configuration file (customizing as you prefer):

Warning: If you ae using a laptop, the below configuration update is not sufficient to get your Nvidia card running! Once you've entered it, please continue reading, as there are important adjustments that must then be made to the configuration before your laptop graphics will work properly.

/etc/nixos/configuration.nix

{ config, lib, pkgs, ... }:
{

  # Enable OpenGL
  hardware.opengl = {
    enable = true;
    driSupport = true;
    driSupport32Bit = true;
  };

  # Load nvidia driver for Xorg and Wayland
  services.xserver.videoDrivers = ["nvidia"];

  hardware.nvidia = {

    # Modesetting is needed most of the time
    modesetting.enable = true;

	# Enable power management (do not disable this unless you have a reason to).
	# Likely to cause problems on laptops and with screen tearing if disabled.
	powerManagement.enable = true;

    # Use the open source version of the kernel module ("nouveau")
	# Note that this offers much lower performance and does not
	# support all the latest Nvidia GPU features.
	# You most likely don't want this.
    # Only available on driver 515.43.04+
    open = false;

    # Enable the Nvidia settings menu,
	# accessible via `nvidia-settings`.
    nvidiaSettings = true;

    # Optionally, you may need to select the appropriate driver version for your specific GPU.
    package = config.boot.kernelPackages.nvidiaPackages.stable;
  };
  ...
}

Laptop Configuration: Hybrid Graphics (Nvidia Optimus PRIME)

In order to correctly finish configuring your Nvidia graphics driver, you must follow the below steps, which differ depending on whether or not you are using a hybrid graphics setup or not. A laptop with hybrid graphics possesses both an integrated GPU (often from the central processor) and a discrete, more powerful Nvidia GPU, typically for performance-intensive tasks. This dual-GPU setup allows for power-saving during basic tasks and higher graphics performance when needed.

Nvidia Optimus PRIME is a technology developed by Nvidia to optimize the power consumption and performance of laptops equipped with their GPUs. It seamlessly switches between the integrated graphics, usually from Intel, for lightweight tasks to save power, and the discrete Nvidia GPU for performance-intensive tasks like gaming or video editing. By dynamically balancing graphics power and battery life, Optimus provides the best of both worlds, ensuring that users get longer battery life without sacrificing graphical performance.

Configuring Optimus PRIME: Bus ID Values (Mandatory)

Before we can continue, we must mandatorily first determine the Bus ID values for both your Nvidia and Intel GPUs. This step will be essential regardless of which configuration you later adopt.

First, install the lshw package in order to be able to use the lshw command, then run:

sudo lshw -c display

You will likely get something like this:

*-display                 
description: i915drmfb
physical id: 0
bus info: pci@0000:01:00.0
logical name: /dev/fb0
version: a1
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list rom fb
configuration: depth=32 driver=nvidia latency=0 mode=2560x1600 visual=truecolor xres=2560 yres=1600
resources: iomemory:600-5ff iomemory:620-61f irq:220 memory:85000000-85ffffff memory:6000000000-61ffffffff memory:6200000000-6201ffffff ioport:5000(size=128) memory:86000000-8607ffff

*-display
product: i915drmfb
physical id: 2
bus info: pci@0000:00:02.0
logical name: /dev/fb0
version: 04
width: 64 bits
clock: 33MHz
capabilities: pciexpress msi pm bus_master cap_list rom fb
configuration: depth=32 driver=i915 latency=0 resolution=2560,1600
resources: iomemory:620-61f iomemory:400-3ff irq:221 memory:622e000000-622effffff memory:4000000000-400fffffff ioport:6000(size=64) memory:c0000-dffff memory:4010000000-4016ffffff memory:4020000000-40ffffffff

Note the two values under "bus info" above, which may differ from laptop to laptop. Our Nvidia Bus ID is 01:00.0 and our Intel Bus ID is 00:02.0. Once you have determined your Bus ID values, add them like this:

/etc/nixos/configuration.nix

{
	hardware.nvidia.prime = {

	# Make sure to use the correct Bus ID values for your system!
	intelBusId = "PCI:0:2:0";
	nvidiaBusId = "PCI:1:0:0";
	};
}

Optimus PRIME Option A: Offload Mode

Offload Mode is available in NixOS 20.09 and higher, and requires an Nvidia card of the Turing generation or newer, and an Intel chipset from the Coffee Lake generation or newer.

Offload mode puts your Nvidia GPU to sleep and lets the Intel GPU handle all tasks, except if you call the Nvidia GPU specifically by "offloading" an application to it. For example, you can run your laptop normally and it will use the energy-efficient Intel GPU all day, and then you can offload a game from Steam onto the Nvidia GPU to make the Nvidia GPU run that game only. For many, this is the most desirable option.

Offload mode is enabled by running your programs with specific environment variables. Here's a sample script called nvidia-offload that you can run wrapped around your executable, for example nvidia-offload glxgears:

nvidia-offload

export __NV_PRIME_RENDER_OFFLOAD=1
export __NV_PRIME_RENDER_OFFLOAD_PROVIDER=NVIDIA-G0
export __GLX_VENDOR_LIBRARY_NAME=nvidia
export __VK_LAYER_NV_optimus=NVIDIA_only
exec "$@"

To enable offload mode, finish configuring your Nvidia driver by adding the following to your NixOS configuration file:

/etc/nixos/configuration.nix

{
	hardware.nvidia.prime = {
	offload = {
		enable = true;
		enableOffloadCmd = true;
	};

	# Make sure to use the correct Bus ID values for your system!
	intelBusId = "PCI:0:2:0";
	nvidiaBusId = "PCI:1:0:0";
	};
}

Optimus PRIME Option B: Sync Mode

Enabling PRIME sync introduces better performance and greatly reduces screen tearing, at the expense of higher power consumption since the Nvidia GPU will not go to sleep completely unless called for, as is the case in Offload Mode. It may also cause its own issues in rare cases. PRIME Sync and Offload Mode cannot be enabled at the same time.

PRIME sync may also solve some issues with connecting a display in clamshell mode directly to the GPU.

/etc/nixos/configuration.nix

{
  hardware.nvidia.prime = {
    sync.enable = true;

	# Make sure to use the correct Bus ID values for your system!
    nvidiaBusId = "PCI:1:0:0";
    intelBusId = "PCI:0:2:0";
  };
}

Optimus Option C: Reverse Sync Mode (Experimental)

This feature is relatively new and may not work properly on all systems (see discussion). It is also only available on driver 460.39 or newer. Reverse sync also only works with services.xserver.displayManager.setupCommands compatible Display Managers (LightDM, GDM and SDDM).

/etc/nixos/configuration.nix

{
  hardware.nvidia = {
    modesetting.enable = true;

    # Reverse sync is not compatible with the open source kernel module
    open = false;

    prime = {
      reverseSync.enable = true;
      # Enable if using an external GPU
      allowExternalGpu = false;

	  # Make sure to use the correct Bus ID values for your system!
      intelBusId = "PCI:0:2:0";
      nvidiaBusId = "PCI:1:0:0";
    };
  };
}

Useful Tips

Using GPUs on non-NixOS

If you're using Nix-packaged software on a non-NixOS system, you'll need a workaround to get everything up-and-running. The nixGL project provides wrapper to use GL drivers on non-NixOS systems. You need to have GPU drivers installed on your distro (for kernel modules). With nixGL installed, you'll run nixGL foobar instead of foobar.

Note that nixGL is not specific to Nvidia GPUs, and should work with just about any GPU.

CUDA and using your GPU for compute

See the CUDA wiki page.

Using Steam in Offload Mode

In order to automatically launch Steam in offload mode, you need to add the following to your ~/.bashrc:

export XDG_DATA_HOME="$HOME/.local/share"

Then, if you are using NixOS Steam, run:

mkdir -p ~/.local/share/applications
sed 's/^Exec=/&nvidia-offload /' /run/current-system/sw/share/applications/steam.desktop > ~/.local/share/applications/steam.desktop

For Flatpak Steam, run:

mkdir -p ~/.local/share/applications
sed 's/^Exec=/&nvidia-offload /' /var/lib/flatpak/exports/share/applications/com.valvesoftware.Steam.desktop > ~/.local/share/applications/com.valvesoftware.steam.desktop

Then restart your graphical environment session (or simply reboot).

Troubleshooting

Booting to Text Mode

If you encounter the problem of booting to text mode you might try adding the Nvidia kernel module manually with:

boot.initrd.kernelModules = [ "nvidia" ];
boot.extraModulePackages = [ config.boot.kernelPackages.nvidia_x11 ];

Screen Tearing Issues

First, try to switch to PRIME Sync Mode, as described above. If that doesn't work, try forcing a composition pipeline.

Note: Forcing a full composition pipeline has been reported to reduce the performance of some OpenGL applications and may produce issues in WebGL. It also drastically increases the time the driver needs to clock down after load.

/etc/nixos/configuration.nix

hardware.nvidia.forceFullCompositionPipeline = true;

Flickering Issues with Picom

~/.config/picom/picom.conf

unredir-if-possible = false;
backend = "xrender"; # try "glx" if xrender doesn't help
vsync = true;

Graphical Corruption and System Crashes on Suspend/Resume

First, ensure that powerManagement.enable = true, as initially suggested in the starting configuration above.

If you have a modern Nvidia GPU (Turing [1] or later), you may also want to investigate the hardware.nvidia.powerManagement.finegrained option: [2]

Black Screen or Nothing Works on Laptops

The kernel module i915 for intel or amdgpu for AMD may interfere with the Nvidia driver. This may result in a black screen when switching to the virtual terminal, or when exiting the X session. A possible workaround is to disable the integrated GPU by blacklisting the module, using the following configuration option (see also [3]):

# intel
boot.kernelParams = [ "module_blacklist=i915" ];
# AMD
boot.kernelParams = [ "module_blacklist=amdgpu" ];