May 8, 2026, 4:27pm 1

Hi everyone,

First of all I want to mention that I’m a Linux beginner, so sorry if I’m missing something obvious or not explaining things well enough. I’m running CachyOS with a dual monitor setup and my second monitor (ASUS ROG Strix OLED XG27AQDMG 1440p 240Hz) gets stuck at 640x480 when connected via DisplayPort to my RTX 5080. My primary monitor (Samsung U28E590 4K) works perfectly on the same GPU.

## System

- Kernel: 7.0.5-1

-cachyos -

Desktop: KDE Plasma 6.6.4 (Wayland)

- GPU: RTX 5080 MSI, driver 595.71.05

- CPU: Ryzen 5 7600

- Mobo: Gigabyte B650M D3HP

## Problem kscreen-doctor shows the OLED with only one mode available (640x480) and 0mm x 0mm physical size, meaning the Nvidia driver isn’t reading the monitor’s EDID. Interestingly, the monitor shows 2560x1440 correctly during the Limine bootloader, so the hardware is fine.

## What I’ve already tried

• options nvidia NVreg_EnableGpuFirmware=0

- drm.edid_firmware=card1-DP-3:edid/oled-1440p.bin (128 byte EDID extracted from /sys/class/drm/card1-DP-3/edid)

- Different DP ports on the GPU

- Updated monitor firmware to latest version Nothing has worked so far.

Has anyone managed to get a similar OLED setup working with Nvidia on Wayland? Any ideas are welcome. Thanks

Did you try a different cable?

I remember a long time ago i was able to manually specify the EDID and it worked, but it was on DVI and X11 no idea if the same method would work today on wayland (and I don’t remember the method, but it’s potentially possible if you can obtain the edid data for your display to manually specify it, which may be worth looking into for you)

A (possibly stupid) question: do you have other monitors plugged in? I also had a weird issue where my resolution for most things, on my main screen, were stuck to 1360x768 (a weirdly specific reso…).

Turns out, I’d forgotten I’d connected an old TV to my GPU via HDMI. KDE Plasma detected it and decided to put that TV on top of my main screen… Meaning, my old TV’s 768p became the standard. Separating them in the settings screen fixed the issue ^^’