I'm using CachyOS with KDE Plasma on Wayland and an Intel UHD integrated GPU. My laptop's built-in display supports 60 Hz and 144 Hz, but I'd prefer to use 120 Hz without switching between the two modes. I was able to create this kind of display override on Windows, but I haven't been able to make a custom resolution or refresh-rate override work on Linux. Attempts with CRU-style settings failed in both Wayland and Xorg, and one of them even caused Xorg to break. Is there a reliable way to add or select 120 Hz for this panel?
2 Answers
If KDE only lists 60 Hz and 144 Hz, the monitor’s firmware or Linux display driver may not be advertising a 120 Hz mode. Custom modes can sometimes be added under Xorg, but they’re much more limited or unsupported on Wayland, and forcing an invalid timing can prevent the graphical session from starting. It may be safer to use one of the modes already shown by KDE unless you can find a panel-specific Linux configuration.
Check KDE’s display settings first under System Settings → Display and Monitor. If 120 Hz is supported and exposed by the panel, it should appear in the refresh-rate dropdown. Plasma on Wayland generally won’t accept the same custom timing overrides used by Windows utilities.

I’m using Plasma on Wayland. The issue is that 120 Hz doesn’t appear as an option, even though I can create and use the override successfully in Windows.