There are some bugs with recent kernels and 6XXX cards. Try kernel 6.5.X and also look at the workarounds here: https://gitlab.freedesktop.org/drm/amd/-/issues/1500

In addition, make sure "Above 4G decoding" is enabled in BIOS/UEFI so you get resize rebar support.

Beyond that, make sure you're using mesa (and not amdvlk) and that's it a version from this year at least (23.X.X)

Linux Mint does not use very recent versions of the gfx drivers for that card (IIRC from last time I checked). My RX6600 therefore had some performance hit when I ran Mint (compared to Windows or other Linux distros). Arguably one could bump the installed versions of xserver-xorg-drivers-amdgpu and mesa-vulkan-drivers to more recent versions. You could have a look into the repo with Synaptic Package Manager and see whether there is a more recent version of the relevant stuff available (perhaps you need to allow for "testing" software source.

Lots of people are reporting poor performance in CS2 on Linux. It's probably not a problem with your system, and more a problem with CS2.

I can provide nothing specifically to the topic at hand, but a great resource is ProtonDB (here the CS2 specific page). You can see which launch options, workarounds, etc work on which distro, GPU, ...

If you get it working, consider posting there, so others can benefit from your knowledge 😀

You're using an RDNA2 card so it's possible your low FPS is caused by this issue. I would try this fix that was mentioned in the comments under that issue to see if your performance improves.

Yeah i get 250fps in it on Windows and 90-120 on Linux. When the game launched smoke grenades didn't even work so i think its safe to say it was untested. Hopefully improvements soon.

Are you using steam native or steam flatpak? I think flatpak might perform better in this case

If possible, maybe try dual booting a Windows install just to test if the games run better there. If they do, it's probably a problem with your system or your configuration, but if not, it's likely your hardware. Might also want to look at your BIOS settings and see if something somehow got reset there, like your RAM clock.

Are you on a laptop using hybrid graphics by chance? Switching to dedicated graphics might help in that case.

I can say about CS, I can run on average 150hz in low setting and FSR on performance, the game seems like shit, but you can. On medium, I can run around 120, and I feel that some maps are heavier.
Do you are playing on Xorg? Usually wayland can have some impact on your game.
Are you experiencing too much stuttering in all games? Recently I discovered my MOBO was trolling and I had to disable some energy related features.
Are you running your game with gamemode? It can make a great difference.
You can also try different kernels https://youtu.be/qNzd57b0h08

Operating System: EndeavourOS KDE Plasma Version: 5.27.8 Graphics Platform: Wayland Processors: 12 × AMD Ryzen 5 3600 6-Core Processor Memory: 31,3 GiB of RAM iirc it is 3200 Mhz but it should not have a so big impact Graphics Processor: AMD Radeon RX 6700 XT

CS2 runs like garbage. -vulkan is most likely a placebo as Source 2 doesn't offer an OpenGL renderer, so it only runs on Vulkan.

The Linux version of the game has barely been tested. The frame times are all over the place. Give it a few weeks and the performance should increase through updates, the issue isn't on your end