Arch Linux

codedcosmos

Member

Registered: 2017-09-25

Posts: 19

How to get Two monitors with 2 different GPU's working

Issue:
I have two monitors, I would like to run each on their own individual GPU, however they do not work in conjunction. I can only ever get one GPU with one monitor working at a time. How can I get both monitors connected, one for each GPU.

Hardware:
Monitor A: DVI + VGA (Primary)
Monitor B: VGA (Secondary)

RX 570: GPU (Primary)
R7-240: GPU (Secondary)

Asus Prime B350 PLUS
Ryzen 7 1700

Notes:
Oddly both gnome and plasma identify both monitors when plugged in, with both GPUs, but refuse to use the second one in any fashion (Extended, Dual, Single Display). Also both are detected with lspci.

Output of lspci | grep VGA:
06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Oland PRO [Radeon R7 240/340]
09:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/580] (rev ef)

More Notes:
Wayland works perfectly, IDK why, but Xorg is still broken, and I will need xorg.

Thanks

Last edited by codedcosmos (2018-07-04 07:12:57)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,435

Re: How to get Two monitors with 2 different GPU's working

Have you seen https://wiki.archlinux.org/index.php/Xo … phics_card ? Not sure how well that will work for integration or if they are to be treated as separate displays that have to have applications explicitly assigned using the relevant environment variable.

codedcosmos

Member

Registered: 2017-09-25

Posts: 19

Re: How to get Two monitors with 2 different GPU's working

Adding the following kernel arguments fixed the issue
radeon.si_support=0 amdgpu.si_support=1
radeon.cik_support=0 amdgpu.cik_support=1

As found on:
https://wiki.archlinux.org/index.php/AMDGPU

Slithery

Administrator

From: Norfolk, UK

Registered: 2013-12-01

Posts: 5,776

Re: How to get Two monitors with 2 different GPU's working

Glad you found a solution.

Please remember to mark this thread [SOLVED].
CoC - How to post

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No, it didn't "fix" anything. It just shifted the brokeness one space to the right. - jasonwryan
Closing -- for deletion; Banning -- for muppetry. - jasonwryan

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