[SOLVED] Switching GPUs

pisauraxtx · 2022-01-26 09:49:00

Hello everyone.
I'm planning on replacing my Nvidia GPU with an AMD one. I'm worried that I will have trouble getting proper video output after the change.
What is the proper way to prepare and complete a video card change on Arch linux?

Right now I'm using the proprietary Nvidia drivers. I have the following packages installed: nvidia, nvidia-settings, nvidia-dkms, nvidia-utils, lib32-nvidia-utils
Should I uninstall these and install the corresponding AMD packages instead before I change the cards? Or should I be fine changing the cards and installing the proper drivers afterwards?
Also, are there any config files I should edit or refresh?

Thank you very much.

Last edited by pisauraxtx (2022-01-27 14:49:15)

V1del · 2022-01-26 10:10:55

Unless you ran nvidia-xconfig to generate a static X layout (or xrandr invocation expecting static monitor names) expecting an nvidia GPU to be present you don't need to do anything at all and could even keep the nvidia packages installed if you wanted.

To that effect it doesn't matter when you uninstall them. The already running system will not inherently implode just because the files on disk disappeared, so you can remove them while you are on the nvidia card, shut off switch the cards and boot back up again. Likewise if you do that beforehand and don't have any explicit references to the nvidia card then the graphics system will just "newly" run on the amd card and the lingering nvidia files have no actual relevance anymore and can then be removed.

Really the most important thing is whether you've created custom configuration that absolutely expects an nvidia card to be present. The normal packages from the repos don't do any of that without user interaction. (Read if you have an /etc/X11/xorg.conf then that's likely autogenerated and should probably be removed, if you want to be sure, post the actual file)

Last edited by V1del (2022-01-26 10:15:35)

pisauraxtx · 2022-01-26 10:32:22

V1del wrote:

Unless you ran nvidia-xconfig to generate a static X layout (or xrandr invocation expecting static monitor names) expecting an nvidia GPU to be present you don't need to do anything at all and could even keep the nvidia packages installed if you wanted.
To that effect it doesn't matter when you uninstall them. The already running system will not inherently implode just because the files on disk disappeared, so you can remove them while you are on the nvidia card, shut off switch the cards and boot back up again. Likewise if you do that beforehand and don't have any explicit references to the nvidia card then the graphics system will just "newly" run on the amd card and the lingering nvidia files have no actual relevance anymore and can then be removed.
Really the most important thing is whether you've created custom configuration that absolutely expects an nvidia card to be present. The normal packages from the repos don't do any of that without user interaction. (Read if you have an /etc/X11/xorg.conf then that's likely autogenerated and should probably be removed, if you want to be sure, post the actual file)

Ah yes, it does look like I have a xorg.conf created by nvidia-xconfig. I did this because I had an issue with DPMS turning off my screen after a few minutes even when videos were running.
Here's what the file looks like:

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 470.57.02

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
EndSection

Section "Files"
EndSection

Section "Module"
    Load           "dbe"
    Load           "extmod"
    Load           "type1"
    Load           "freetype"
    Load           "glx"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "BenQ RL2450H"
    HorizSync       30.0 - 83.0
    VertRefresh     50.0 - 76.0
    Option         "DPMS" "Disable"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "NVIDIA GeForce GTX 1050 Ti"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "nvidiaXineramaInfoOrder" "DFP-0"
    Option         "metamodes" "nvidia-auto-select +0+0"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

So there is an explicit mention of the GPU vendor and model in there.
I noticed that when running "Xorg :2 -configure", the resulting file also makes explicit mention of the driver used, but not of the model:

[...] Section "Device"
        Identifier  "Card0"
        Driver      "nvidia"
        BusID       "PCI:43:0:0"
EndSection [...]

Should I try to replace the config file with a new one now? Or should I take care of that when the new video card is built into the computer?

V1del · 2022-01-26 10:48:58

Remove the config and don't generate one. Xorg has autodetection that does most of the things automatically and correctly (unless you add a Device section which will disable the autodetection in favor of the device section). If you want to disable DPMS globally there are multiple monitor and driver agnostic ways of configuring that mentioned in: https://wiki.archlinux.org/title/Displa … _DPMS_in_X see the part with the ServerFlags and/or the complete disabling of DPMS as a whole which are not bound to any particular monitor (the monitor identifier names will change between different Xorg drivers, so if you wanted to configure that seperately you'd need to do that after checking what they are called with the amdgpu/modesetting driver).

Last edited by V1del (2022-01-26 10:51:59)

pisauraxtx · 2022-01-27 14:48:57

V1del wrote:

Remove the config and don't generate one. Xorg has autodetection that does most of the things automatically and correctly (unless you add a Device section which will disable the autodetection in favor of the device section). If you want to disable DPMS globally there are multiple monitor and driver agnostic ways of configuring that mentioned in: https://wiki.archlinux.org/title/Displa … _DPMS_in_X see the part with the ServerFlags and/or the complete disabling of DPMS as a whole which are not bound to any particular monitor (the monitor identifier names will change between different Xorg drivers, so if you wanted to configure that seperately you'd need to do that after checking what they are called with the amdgpu/modesetting driver).

Thank you. I deleted the xorg config and built the new GPU into my computer today and it just worked. I uninstalled everything that smelled like Nvidia except for some dependencies that Steam needs. I didn't run into any issues.

It remains to be seen whether DPMS works properly with the new card now or if I have to change any settings there.

I'm gonna mark the topic as "solved" now.

Arch Linux

#1 2022-01-26 09:49:00

[SOLVED] Switching GPUs

#2 2022-01-26 10:10:55

Re: [SOLVED] Switching GPUs

#3 2022-01-26 10:32:22

Re: [SOLVED] Switching GPUs

#4 2022-01-26 10:48:58

Re: [SOLVED] Switching GPUs

#5 2022-01-27 14:48:57

Re: [SOLVED] Switching GPUs

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