Specify config based on number of GPU

Help
1

Hi everyone. I’ve been a NixOS user for the past couple of months, really liked the philosophy of the project.

I have a configuration setup for my laptop with a dual-graphics-card-configuration.nix made to generate the dual GPU configuration

{ config, pkgs, ... }:

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

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

  hardware.nvidia = {

    # Modesetting is required.
    modesetting.enable = true;

    # Nvidia power management. Experimental, and can cause sleep/suspend to fail.
    # Enable this if you have graphical corruption issues or application crashes after waking
    # up from sleep. This fixes it by saving the entire VRAM memory to /tmp/ instead 
    # of just the bare essentials.
    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 = 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;
    
   prime = {
	sync.enable = true;

	nvidiaBusId = "PCI:0:1:0";
	amdgpuBusId = "PCI:0:4:0";
	};
  };

}

And in my configuration.nix I do :

{ config, pkgs, ... }:

{
  imports =
    [ # Include the results of the hardware scan.
      ./hardware-configuration.nix
      ./dual-graphics-card-configuration.nix
    ];
}

So what would you be your way to specify NOT to launch this part of the configuration if I’m not on a laptop with the right conditions ?
Many thanks in advance to everyone !

2

Please use triple-backticks to denote start/end of code blocks, it makes it much easier to read.

Write a separate config for the separate system, that’s what you’d have to do anyway…

3

You can specify the file that contains your configuration (i.e. nixos-rebuild switch -I nixos-config=/path/to/config/file.nix, or using flakes). This would allow you to have multiple configurations in the same place (like a git repo in your home folder), and sharing the common parts.