Dual GPU notebook with extra eGPU

0mark · 2022-11-19 13:22:21

Because the more the merrier. Or so they say. First, i got it to work in a crude way. Now i want it to work nicely. Or maybe i am just curious. I tried around a bit and poked the internet, but now i am at the point where i would rather ask around if there is already some experience around.

But first a short run-down of what i've got:

Notebook with Intel and Nvidia onboard
Thunderbold connected Nvidia
Xorg running either solely on the eGPU: works fine, easy to setup, fast and reliable (so far)
Xorg running on the Intel with prime offloading on the eGPU: so far _only_ works after disabling the internal Nvidia (unbound from the driver). But then works fine.
I also had a quick try with wayland. Although it seems that the eGPU is there (nvtop and dmesg output), i could not get anything to use it. Only the internal nvidia was usable.

Sidenote: If anyone is interested in details about one of the two working setups, i can write it down

For me it would be ideal if i could hotplug the eGPU. From what i've read this should be possible with Wayland. But i found nothing about it with thre GPUs. So, did anyone ever got such a thing to work? Preferably with hotplug, but just in general three (or more) GPUs with the ability to use either for games.

Next, might there be any way to at least warm-plug the eGPU on Xorg? Thinking in the direction of having my Desktop run via VNC so i can restart the X server without loosing my session. Only Games and such would run outside. Would love to hear if someone had done something like this.

Third, i thought about just starting a second X session directly on the eGPU. I tried, but i never got it to run on the eGPU while the original X session was running. Second X on the Intel no problem, though Or if anybody knows if the nvidia driver will bind to a hotplugged card when the driver is already in use? I guess not, which would explain my troubles here.

And in general, i would like to hear how other people deal with a setup like this. Maybe much better solutions are already out there

Thanks in any case

Last edited by 0mark (2022-11-19 13:52:13)

0mark · 2022-11-20 07:15:17

A short notice: I could make in run with wayland and hotplug. Although i think there is probably a more elegant way. I just unbind the internal Nvidia GPU and then it work:

echo "0000:01:00.0" > /sys/bus/pci/drivers/nvidia/unbind

Note that "0000:01:00.0" should match your card (lspci output):
01:00.0 VGA compatible controller: NVIDIA Corporation TU106GLM [Quadro RTX 3000 Mobile / Max-Q] (rev a1)

I could not find a way to select which card is to be used, but disabling the other one works. Not really a nice solution, and i'm pretty certain there is a decent way which i just could not find out.

Arch Linux

#1 2022-11-19 13:22:21

Dual GPU notebook with extra eGPU

#2 2022-11-20 07:15:17

Re: Dual GPU notebook with extra eGPU

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