Compatibility Report

• Name of the game with compatibility issues: Cyberpunk 2077
• Steam AppID of the game: 1091500

System Information

• GPU: NVidia 2080ti
• Video driver version: Driver Version: 580.95.05
• Kernel version: Linux archlinux 6.17.5-arch1-1
• Link to full system information report as Gist:
• Proton version: Proton 9

I confirm:

• [ yes] that I haven't found an existing compatibility report for this game.
• [ yes] that I have checked whether there are updates for my system available.

Symptoms

Everytime I launch the game, it starts with lower FPS than expected. Then, after I alt+tab one time, and tab back in, I get a permanent 20+fps boost for the rest of the session.

Reproduction

Launch cyberpunk
Load save
Stand still, 50fps
Alt+Tab
Tab back into the game
75+Fps and the boost lasts for the entire session

100% Reproducable everytime I play the game. I have to do this everytime I play the game or it runs worse.

Here is a long and detailed Reddit post including Video about the issue
https://www.reddit.com/r/linux_gaming/comments/1og5dee/alttabbing_gives_me_a_20fps_boost/

THINGS I HAVE TRIED AND RULED OUT:

-using Proton 9 / Experimenta/ Proton GE
-Window manager doesn't matter. Happens on Plasma X11 Compositing off, Openbox, Labwc. Same behaviour
-Windowed mode gives permanent 20fps loss, only game in Fullscreen + alt+tab, gives 20fps Boost
-Not Wayland , X11, or Desktop Environment issue
-Doesn't have anything to do with hardware overheating or anything like that
-Tried messing with CPU Governor, Performance, Balance, etc. Doesn't matter
-Can't reproduce the issue in other games like Resident Evil 4 Chainsaw Demo, might just be Cyberpunk
-Its not just an overlay bug, its genuinely smoother
-Same reporting in Mangohud and Steam Overlay
-Turning off VRR on monitor doesn't matter

Pretty stumped at this point. MIght just be a more fundamental driver/vulkan/dxvk issue that only affects 2000 RTX series Nvidia cards?. I asked Chatgpt about it, and it said, this, does anyone know if this is plausible or accurate?

Chatgpt:
What’s happening is that Cyberpunk 2077, when launched through Proton using VKD3D on Linux with an NVIDIA GPU, initially creates its DirectX 12 swapchain in a composited or vsynced state, which VKD3D translates into Vulkan’s VK_PRESENT_MODE_FIFO_KHR. This mode queues frames and synchronizes them with the compositor, introducing latency and lowering performance — that’s why your framerate starts around 50 FPS. When you Alt+Tab out of the game and back in, the window loses and regains focus, forcing VKD3D to tear down and recreate the swapchain. On this recreation, the driver (and sometimes VKD3D itself) switches from FIFO mode to VK_PRESENT_MODE_IMMEDIATE_KHR, which bypasses the compositor and sends frames directly to the display, effectively enabling “true” exclusive fullscreen. That change instantly boosts GPU throughput and raises FPS to around 75+, where it then remains stable for the rest of the session.