nixos-hardware/lenovo/legion/15ach6h/README.md

Introduction

Due to the introduction of DDG feature, you may toggle DDG frequently, so for the default settings of this laptop, we use "specialization" feature of Nix so that you can easily select the required graphics card driver in the startup menu.
But It will slow down NixOS evaluation by factor 2 and increase memory usage.
So if you don't need specialization feature, you can just use hybrid only configuration or nvidia only (DDG only) configuration

Using multiple drives with this configuration

When using more than one drive, the value of hardware.nvidia.prime.amdgpuBusId will change from the default of PCI:5:0:0.

Make sure you override this default in your personal configuration. For two drives, it should be PCI:6:0:0.

Setup at the time of testing

$ nix-info -m
 - system: `"x86_64-linux"`
 - host os: `Linux 6.0.9, NixOS, 22.11 (Raccoon), 22.11beta19.c9538a9b707`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.11.0`
 - channels(root): `"nixos-22.11"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

$ lspci
...
01:00.0 VGA compatible controller: NVIDIA Corporation GA104M [GeForce RTX 3070 Mobile / Max-Q] (rev a1)
...
06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Cezanne (rev c5)
...