Wayland Refresh Rate Capped at 50Hz (Half Rate) on 100Hz Monitor - Dell 7567 (Works fine on X11/Windows)

Issues & Assistance
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1

Hi everyone,

I’ve been using CachyOS with KDE on my Dell 7567 (i5-7300HQ / GTX 1050) for almost a year now without any issues. However, I recently bought a 100Hz monitor and I’m running into some trouble.

The Issue:
Although the system settings correctly identify the 100Hz refresh rate, the actual output is consistently capped at 50Hz. Vsync locks games exactly at 50 FPS and TestUFO also reports a steady 50Hz.

Troubleshooting so far:

This is happening on a fresh installation of CachyOS and everything works perfectly at the full 100Hz on X11 sessions and on Windows, so I’ve ruled out hardware or cable (HDMI) limitations.
I also tested other Wayland DEs (like GNOME) and the same 50Hz cap occurs.
I’ve tried several suggestions found online regarding DRM and KWin variables, but none have resolved the issue.

Has anyone dealt with this specifically on Pascal-series mobile GPUs or CachyOS? Does anyone have any suggestions on what to try next?

Thanks in advance!

2

Hello,

I assume neaveau driver is in use.
My suggestion would be to try nvidia-580xx-dkms driver.

3

Thanks for the heads-up! I actually forgot to mention that I’m already using the latest proprietary Nvidia drivers provided by CachyOS.

4

Have you tried using a DisplayPort cable? I’ve seen a lot of Nvidia users have this exact same issue with HDMI. I thought this might have been a kwin bug, but you seem to have the same issue with mutter too… Strange. I guess I would blame the Nvidia driver. You could try using an older driver or, again, a DisplayPort cable. In general, DP works better than HDMI with Linux graphics drivers. So if you have the option to avoid using HDMI, like with a monitor then do so. TVs don’t really support DP and so HDMI is the only option and a bunch of people have had to go into the TV’s settings and disable the “auto” configuration on the HDMI port to get the TV to work at 60+ Hz with the Nvidia Wayland driver.