2 Different GPUs 6 Screens

Sparknotes version - trying to get an RTX 3050 and an RTX 4090 to each output 3 DisplayPort ports on GNOME. Is this even possible or am I trying something stupid? I’m not trying to game on them all concurrently, I just want the screen real estate. I am using the proprietary nvidia drivers on Arch.

This seems to work fine on Windows 10 (although one of the screens was smashed in shipping so it could be only outputting 5, but Windows recognizes all 6). I’m only able to get the 3 screens attached to the 4090 to output concurrently over the X Screen 0 configuration, and the remaining 3 are recognized in nvidia-settings but shown as (Disabled).

Mosaic is not an option with these cards I believe and have even tried to configure it to see if it works but to no avail. I’ve tried to set nvidia-drm.modeset=1 per a generix post but xrandr still only sees one provider.

If anyone can help provide some traction on which way to go here I’d really appreciate it as I seem to not be getting anywhere on solving this. Perhaps it’s impossible and I misunderstood how the screen limit on GeForce cards plays out in the real world.


Appreciate the link and the help but unfortunately that’s the one of yours I came across while googling and had no luck with. Deleting /etc/X11/xorg.conf leads to a blinking cursor and black screen, where I can still log in by going to one of the other ttys but cannot startx just the same and therefore the xrandr --listproviders command would just error. If I left the xorg.conf file alone and added the kernel parameter it didn’t seem to have any effect.

I genuinely tried googling from there but again seemed ineffectual. I have a feeling I’m doing something stupid but at the least am glad that such an experienced person pointed me to a post I tried to follow. Thoughts on if I’m not setting the kernel parameter in grub correctly or what I might be missing?

I was able to get it working. For the few out there to which this may also apply, the key was adding some kernel modules to the initramfs (nvidia, nvidia_modeset, nvidia_uvm, nvidia_drm) per the page linked below on the Arch Wiki:

Thanks for the drm kernel parameter setting suggestion - it reinforced that I was going down the right rabbit hole.

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