An Unholy GPU Alliance Under Linux

I’ve never tried using two different GPUs for the same session before. Are you using an AMD and Nvidia card simultaneously?

I did on Ubuntu with the 415 driver download from the Nvidia site…after reboot it still wouldn’t work. On Ubuntu proper, after the proprietary driver is loaded it goes into a boot loop on GDM3. If I plug all 3 displays into the Vega 64 exclusively it still won’t boot GDM3, but, if I then select Wayland…Boom it all boots up fine. Sooo…it’s very wonky once the proprietary driver is added to the stock Ubuntu mix…repo or otherwise.

Yes…I have a Vega 64 & a 1080Ti on the same rig.

I should’ve looked at earlier posts in the thread.

I have a similar setup but my Radeon is completely stubbed out so only the Nvidia gets a driver and everything works. I’m hoping someone else can give some input here but I have nvidia in my system and none of these problems. It’s making me wonder if theres a conflict in using both cards at the same time. As people have said earlier in the thread, it should work in theory, but I would consider this setup to be an edge case. We may be running into some bug in display drivers or Xorg. My last question for now is: does everything work fine if you remove a card?

I haven’t tried that. I’ve got my Frankenstein-system assembled and I’ve just been trying to attack the problem from a software side.

But Linux does allow Mesa & Nouveau to run both cards independently very nicely. Two displays are on HDMI on Vega & a huge 34 in display on Nvidia with Nouveau. But if you add the proprietary Nvidia anything…all hell breaks loose.

I guess I should just choose one and pull the other. I am leaning towards my Vega but I worry that the Nvidia would’ve been the better performant Card on Steam on Linux. Thoughts? Opinions? Biases? I’ll take all constructive feedback.

Also…side note…your name is badass! As a geeky parent of a Toddler…I love it!

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Nouveau and Radeon are both mesa drivers so it makes sense that they would work together… I would start by trying with just a single card and we can figure out if that’s actually what we’re dealing with here. There might still be a solution out there.

If worst comes to worst i can unstub my 290x and try it on my system and see if I can make it work on OpenSUSE.

So, which to choose. The Green Pill or the Red Pill? Which works better (for Steam) on Linux?

BTW…I acknowledge I’m nuts for putting both those cards in a single system. What can I say…I love choice!

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Really…well the more you know!

With the cards you have you’ll be fine either way. Each has their pros and cons. Nvidia can be a pain if you’re on the bleeding edge with a rolling release distro, whereas AMD flourishes on the bleeding edge. Nvidia will probably get you better performance in more situations. But I don’t think you would be wrong for choosing either.

Also you could always run the second card as a GPU for passthrough to a VM if your system is set up for it. That’s what my AMD card is for (even though i never use it anymore)

Hmm…so you run all on Team Green and use Team Red as an after-thought. Ok…well…you have been IMMENSELY helpful. The insights you’ve provided do suggest I need a “Coming to Jesus Moment” with which one I must choose to run my rig and with my Linux / Windows aspirations.

Did more digging and it looks like it should be possible but with some major caveats and some serious limitations in functionality. People are having trouble getting the cards to work in the same system even without using both for displays.

You would probably have to run xinerama with different X sessions, which I have never had to do before and is beyond my usefulness. If you wish to persue it further, here is some material that I found; some outdated but hopefully still helpful.


https://community.amd.com/thread/168095
https://bbs.archlinux.org/viewtopic.php?id=179549
https://bbs.archlinux.org/viewtopic.php?id=235565

You have been awesome sir or ma’am. Do not sell yourself short. I value your time and dedication to my little humble issue.

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Sorry I didn’t reply earlier, but I’ve been having some account issues. It looks like you got your issue addressed.

My setup has evolved a bit. I now have a Vega 56 (flashed with a Vega 64 BIOS) dedicated to Fedora 28, and a 1050 Ti assigned to a Windows 10 VM. My old Dell monitor developed some burn-in, so I switched to an Acer X270H-B. Lower resolution, but up to 144Hz refresh rate. And it has 2 DisplayPort and 1 HDMI ports. So now all I have to do to switch between VM and host is hit the input selector on the monitor. The Vega is running with a fairly recent amdgpu/Mesa driver, and the 1050 Ti has the latest Nvidia Windows driver.

So after a lot of drama I discovered that it is possible to reinstall Windows so many times that it simply refuses to update. So I just said, screw it…I have Steam Play (ala Proton) on Linux for the non-Linux games…just go all in on Linux without Windows.

Your post does give me an idea :bulb: though …I can VM Windows on my Ubuntu LTS partition and just dedicate 1 TB SSD and a seperate 3 TB for Steam…and just use a eGPU connected to a Thunderbolt 3 connection. Probably way more secure of a setup in light of how Windows leaks personal info.

I have 3 questions.

Are you using Gnome/Wayland? Nvidia proprietary drivers don’t play nice with Wayland.

Did you blacklist the Nouveau driver?

What does your X log say when you black screen?