Using a dedicated GPU exclusively instead of as-needed(Non-laptop + Wayland + Nvidia specifically)

FAQ and Tutorials
1

First off, apologies if this isn’t Cachy specific. Not quite sure where else to start asking.

Right now, my system defaults to using my system’s iGPU running via HDMI 2.1 while turning on my Nvidia GPU as needed.

For the most part this is ok; however I was considering a high refresh rate monitor at some point and I believe 2.1 tops out at 120hrz(at 4k, which is my monitor resolution).

Is there a way to run everything completely off of my Nvidia GPU?

After searching for awhile all the references that seem to turn up involve laptops, I was hoping someone might have some clues about how to go about things on desktops(or is it basically the same process?).

If it matters, I’m using KDE on Wayland. I have seen some references to tweaking what I believe are X11 related things but Wayland has been more stable for me so I’d like to stick to that if possible.

EDIT : forgot to mention I have tried disabling the iGPU from the bios; however I briefly couldn’t get a signal from anything, even when unplugging my Nvidia card so a software only solution would be preferable if that exists.

Thanks!

2

Hooking the HDMI port to your NVIDIA GPU should do the trick.

3

Adding a different aspect:

How about connecting the monitor

  • via USB-C Alt Mode with embedded DisplayPort (1.4)
  • or by dedicated DisplayPort (1.4/2.0/2.1)?

HDMI is usually for cheap/consumer stuff, DisplayPort for more demanding usecases.

4

Doh. Turns out I was dumb and this is all just user error. Thanks for the help folks.

I had tried to run things off my Nvidia card initially by just having that plugged in. However, I couldn’t get any kind of display signal which is why I ended up using the iGPU for display till now.

I didn’t think it was the issue at first because it had been fine up until that point but it seems like it might be a cable, or maybe even a monitor issue; after fiddling with the cable and the ports I can get a signal now, even with the motherboard now set to not disable the iGPU.

5

I had to create a script to run at boot even with thunderbolt port out dGPU to monitor on laptop:

[Unit]
Description=Power-off gpu

[Service]
Type=oneshot
ExecStart=/bin/sh -c 'echo 1 >/sys/devices/pci0000:00/0000:00:02.0/remove'

[Install]
WantedBy=multi-user.target

This shuts off the internal iGPU and forces all output to NVIDIA.