I’m trying to figure out why Fedora KDE Plasma only gives me 2560×1440 at 120 Hz, even though my monitor supports up to 240 Hz.
Hardware:
GPU: AMD Radeon RX 6700 XT
Monitor: ASUS ROG Strix XG27AQDMG
Connection: DisplayPort
OS: Fedora KDE Plasma 44
Session: Wayland
Kernel: 6.19.10-300.fc44.x86_64
Mesa: 26.0.3-4.fc44.x86_64
KWin: 6.6.4-2.fc44.x86_64
The monitor works at 2560×1440 144 Hz in Windows on the same PC
HDMI?
Maybe the driver is limited and cannot support 240Hz, because 2560x1440@240hz might exceeds the available HDMI2.0 bandwidth ( didn’t check though). You could try connecting the Display via DisplatPort instead of HDMI.
Update:
oops, missed the fact that you’re using DP.
This may need the hdmi 2.1 changes that AMD engineers are adding to the Linux kernel at the moment. But I am guessing.
why are you using a kernel this old? please try with newer mesa drivers and newer kernel, a fully updated f44 please
worth to discard the displayport connector and cable, try with hdmi, should be enough for that refresh rate at that resolution
DP is always better than HDMI as it is the native interface of the GPU.
It may also be related to the DP cable between the PC and the monitor. Have you verified that you are using the latest and best DP cable? Older cables are not able to support the highest settings on newer monitors & GPUs.