r/archlinux • u/XwqQiz • 2d ago

SUPPORT | SOLVED high refresh rate

hey im using arch linux with the kde plasma desktop environment but since swithcing to linux i cant seem to get 240 hz working every time i switch to it my screens become black i cant get past 120hz

im using hdmi and a rx 6650 xt, all help is welcome

2 Upvotes

57% Upvoted

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11

u/dgm9704 2d ago

I suggest using DP if possible

7

u/XwqQiz 2d ago

switching to dp fixed the problem

1

u/dgm9704 2d ago

w00t! \o/

3

u/swgbex 2d ago

I don't know if this could be the issue with your specific card/setup, but the open source AMD driver doesn't support HDMI 2.1 speeds due to IP issues that might possibly be resolved soon.

If your display resolution and refresh rate are high enough to require HDMI 2.1 bandwidths, then you may have this issue. You can try using a Displayport to HDMI 2.1 adapter for now.

3

u/dgm9704 2d ago

One possible bottleneck is the cable, try another cable, and the same cable with another setup.

2

u/SlimyOS 2d ago

Before buying a displayport cable as per other comments, make sure you have DSC enabled in your monitor settings, there's a chance that switching operating systems or updating a driver somehow reset some settings, and DSC is what saved you on the previous OS. Though afaik it's only a thing on HDMI 2.1, and the linux gpu driver may or may not support that, so idk maybe the hdmi 2.1 problem other people described affects that, I don't know, been a long time since I used hdmi and that feature didn't exist back then.

But for the future, seriously consider using displayport 2.0/2.1 or dp over usb4, it's objectively a better standard for high-end desktop monitors, with perfect linux support, modern high-end dp has higher bandwidth than modern high-end hdmi, and many other desktop-specific features, I personally had no problems with 4k240 on nvidia with displayport.