I have been experiencing a horrible laggy stutter at all times during gameplay in several of my games. I mostly focused on a game that I know should run incredibly well, Elite:Dangerous. Elite is also by far the worst offender on my list. Most other games that stutter are minor, but Elite is completely unplayable in any area remotely populated. See this video to demonstrate: (link) This test in this video was done without any Proton flags and was using the default compatibility option, but all of the changes below either completely prevented the game from launching or made it run exactly the same.

It's also worth mentioning that this is the best it gets. In actual missions, it will drop to below 10 FPS average sometimes with half a second between frames. Oddly enough, when increasing the resolution and graphics settings, the performance is almost identical.

My computer was able to run this game at a buttery-smooth ~100+ FPS at 4K Ultra under Windows most of the time and handled VR like a champ. The issue under Proton affects several games. Here are just a few examples of games that should be more than fine on my system and worked well under Windows. I also made sure to let shaders compile both at game launch and in-game if applicable for each of these. The amount of stutter varies wildly from game to game, but these all share similar symptoms:

• Elite:Dangerous
• Spider-Man (Original, MM and 2)
• Forza Horizon 4
• BeamNG.Drive (DirectX and Vulcan)
• Uncharted 4
• GTA V Enhanced
• Planet Coaster 2

I also have several games that run completely fine on Ultra settings or have nearly imperceptible stutter (albeit with some DLSS in places):

• Just Cause 3
• Cyberpunk 2077
• God of War: Ragnarock
• Crysis 2 Remastered
• Teardown
• DiRT 4
• Just about any indie game

otacon@bazzite:~$ fastfetch
                                            otacon@bazzite
     %%%%%%====%%%%%%%%%%            
   %%%%%%%%    %%%%%%%%%%%%%%             󱋩  bazzite-deck-nvidia:stable 
  %%%%%%%%%    %%%%%%%%%%%%%%%%           󰣛  Bazzite
  %%%%%%%%%    %%%%%%%%%%%%%%%###           Linux 6.17.7-ba20.fc43.x86_64
  %%%%%%%%%    %%%%%%%%%%%%%######        󰅐  20 hours, 38 mins
  ==                  =======######  
  ==                  =========#####      󰾰  B760I AORUS PRO (-CF)
  %%%%%%%%%    %%%%%%%####======#####     󰻠  12th Gen Intel(R) Core(TM) i5-12600K (16) @ 4.90 GHz
  %%%%%%%%%    %%%%%#######=====#####     󰍛  NVIDIA GeForce RTX 4070 [Discrete]
  %%%%%%%%%    %%%#########=====#####       7.09 GiB / 31.09 GiB (23%)
  %%%%%%%%%    %%##########=====#####       1.63 TiB / 1.82 TiB (89%) - btrfs
  %%%%%%%%%====###########=====######     󰍹  3840x2160 @ 60 Hz in 72" [External]
   %%%%%%%%====#########======######      󰖺  Microsoft X-Box 360 pad 0
    %%%%%%%=====#####========######       󰖺  Sony Interactive Entertainment Wireless Controller (100%)
     %%%%###===============#######        󰖺  Sony Interactive Entertainment Wireless Controller Motion Sensor)
      %#######==========#########    
        #######################           󰕮  KDE Plasma 6.5.3
          ###################               KWin (Wayland)
              ###########                   bash 5.3.0
                                            Ptyxis 49.2
                                          󰏖  2741 (rpm), 56 (flatpak), 25 (brew)
                                          
otacon@bazzite:~$ MESA_VK_DEVICE_SELECT=list vulkaninfo
WARNING: [Loader Message] Code 0 : terminator_CreateInstance: Received return code -3 from call to vkCreateInstance in ICD /usr/lib64/libvulkan_dzn.so. Skipping this driver.
selectable devices:
  GPU 0: 10de:2786 "NVIDIA GeForce RTX 4070" discrete GPU 0000:01:00.0
  GPU 1: 10005:0 "llvmpipe (LLVM 21.1.6, 256 bits)" CPU 0000:00:00.0

I'm running Bazzite in desktop mode. I have tried all of the following steps (in Elite) that I came across while trying to solve this on my own to no avail:

• Full system update
• Proton settings:
  • GE Proton 10-17
  • Proton 9 Stable
  • Proton 10 Stable
  • Proton Experimental
  • Tested Flags:
    • PULSE_LATENCY_MSEC=60
    • DRI_PRIME=1
    • DXVK_CONFIG="dxgi.maxDeviceMemory=11000” (I have a 12GB card)
    • mangohud (does not launch)
    • gamemoderun
    • gamescope (does not launch)
• Disabled iGPU
• V-Sync/Frame Limiter On/Off
• Lowered graphics to minimum, set resolution to 1080p
• Fullscreen and Borderless

I have done hours of searching both DDG and Google and have run out of relevant things to search. I've been at this for about a month now with no progress whatsoever. Any help on this would be massively appreciated.

If it wasn't already apparent, I am long-past the point of shotgun troubleshooting and am willing to try just about anything to resolve this.

Edit 1: I just did the UFO Test, and realized that it occasionally has a minor hiccup, but nothing major in windowed mode, but going into fullscreen and moving my mouse around replicates this same stutter that my games experience.

Edit 2: Selaco of all things is experiencing this, a game running in GZDoom. Both OpenGL and Vulcan produce the same result.