Shadow glitches (and poor performance) in Skyrim: SE

This is an automated archive made by the Lemmit Bot.

The original was posted on /r/linux_gaming by /u/_nak on 2023-06-27 20:55:52+00:00.

Hello everyone. I've recently switched my gtx 1050 for an rx 580, which is definitely an upgrade - except for playing Skyrim. The shadows appear as lines forming squares and smudge around. Performance is also a lot worse than on my gtx 1050, which might be a related issue and definitely shouldn't be the case.

I can't find anyone with a similar problem. I verified game files, reinstalled Skyrim, set up new prefixes, switched my installation drive, uninstalled and reinstalled drivers, different graphics settings, switching between Wayland and X11. No errors in steam or journal.

I'm completely clueless. Here's a video of it in action: https://streamable.com/2apmyw

And for those who don't want to load a video, here are two screenshots (showing different shadow detail levels): https://imgur.com/a/ska8HTI

I'm on 6.3.9-arch1-1 running KDE Plasma Plasma 5.27.6. Ryzen 5 2600, 16GB RAM.