Dual discrete graphics card AMD + Nvidia, choosing which card is used by application

[runta]

I have a GT 710 and a RX 6800 XT, each has a separate monitor.
What I would like to achieve is using the 710 to accelerate the desktop and software like browsers while using the 6800 XT for games and other GPU heavy tasks.

What I’ve managed to get to so far is the 710 displaying both monitors and rpcs3 emulator running on the 6800 XT because it has the option to choose a GPU.

However I can’t find a way to force games to use the 6800 XT, I’ve tried DRI_PRIME=1, prime-run and __NV_PRIME_RENDER_OFFLOAD=1 but none of these work probably because they are designed to work with integrated CPU graphics.

I also tried installing bumblebee but that completely breaks X11 after a restart.

Is this idea a complete pipe dream? Is there a way I can get this working?

Thank you for reading and any help.

[cscs]

Take this with a bit of salt to use mhwd, rather than packages directly … but
https://wiki.archlinux.org/title/PRIME

[runta]

Thanks for the advice cscs.

Turns out I was severely over complicating things. Had to reinstall Manjaro from scratch and go from there because I nuked xorg completely by mistake, kept on booting to a black screen with only a cursor and couldn’t recover from that even in tty2 heh.

Before installing any video drivers I decided to check the behavior of DRI_PRIME=1 and it works as intended. Causing the application to use the selected GPU.

What I did the first time around is use the “Auto Install Proprietary Driver” button in the Hardware Configuration settings menu. This installed the video-hybrid-amd-nvidia-prime drivers which don’t seem to be necessary for my set up.

I think mhwd is assuming one of the cards is an iGPU and installing the hybrid drivers when they probably won’t work as intended given both GPUs are dedicated and probably don’t have the necessary hardware configuration for Prime to work at all.

Not sure if this is intended behavior or maybe something that could be changed or at least warn users about if they don’t have an actual iGPU.

Hope this helps someone if they run into a similar issue and please correct me if I am wrong.

Edit: The reason this seems to work is because by default the nouveau drivers are used for the 710. Installing the proprietary drivers for Nvidia breaks DRI_PRIME=1 and the 710 ends up being always used. For now I’ll just stick to the nouveau drivers.