grimm-nixos-laptop/modules/nvidia.nix

{ config, pkgs, lib, ... }:
{
  boot.extraModulePackages = [ config.boot.kernelPackages.nvidia_x11 ];
hardware.nvidia = {
    # Modesetting is required.
    modesetting.enable = true;

    # Nvidia power management. Experimental, and can cause sleep/suspend to fail.
    powerManagement.enable = false;
    # Fine-grained power management. Turns off GPU when not in use.
    # Experimental and only works on modern Nvidia GPUs (Turing or newer).
    powerManagement.finegrained = false;

    # Use the NVidia open source kernel module (not to be confused with the
    # independent third-party "nouveau" open source driver).
    # Support is limited to the Turing and later architectures. Full list of 
    # supported GPUs is at: 
    # https://github.com/NVIDIA/open-gpu-kernel-modules#compatible-gpus 
    # Only available from driver 515.43.04+
    # Currently alpha-quality/buggy, so false is currently the recommended setting.
    open = true;

    # 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.beta;
  };

  hardware.nvidia.prime = {
    sync.enable = true;
#    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";
  };

  specialisation = {
    on-the-go.configuration = {
      system.nixos.tags = [ "on-the-go" ];
      powerManagement.cpuFreqGovernor = lib.mkForce "powersave";
      hardware.nvidia = {
        prime.offload.enable = lib.mkForce true;
        prime.offload.enableOffloadCmd = lib.mkForce true;
        prime.sync.enable = lib.mkForce false;
      };
    };
  };
}