Fedora 41 KDE chrome apps laggy with 4080 Super

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1

Hi everyone,

I wanted to give KDE a spin for a change instead of gnome. So far it’s quite nice and polished, but I am having a bit of a frustrating time with lag.

Works fine:

  • Firefox
  • Plasma UI
  • Alacritty
  • Dinkum
  • Age of Empires 2 Definitive

Laggy input / low framerate:

  • Discord
  • Google Chrome
  • Steam (flatpak and from nonfree repo)
  • 1Password
  • Signal

I believe the pattern here is anything electron/chrome related.

I’ve tried disabling GSP firmware with sudo grubby --args="nvidia.NVreg_EnableGpuFirmware=0" --update-kernel=ALL and I’ve tried rebuilding kernel modules with sudo akmods --kernels $(uname -r) --rebuild.

Nothing seems to help and I’m running out of ideas. Does anyone have any other ideas? Thanks!

modinfo -F version nvidia
565.77

inxi -Gxx
Graphics:
  Device-1: NVIDIA AD103 [GeForce RTX 4080 SUPER] vendor: PNY driver: nvidia
    v: 565.77 arch: Lovelace pcie: speed: 5 GT/s lanes: 16 ports: active: none
    off: DP-1,DP-2 empty: DP-3,HDMI-A-1 bus-ID: 3e:00.0 chip-ID: 10de:2702
  Device-2: Logitech HD Pro Webcam C920 driver: snd-usb-audio,uvcvideo
    type: USB rev: 2.0 speed: 480 Mb/s lanes: 1 bus-ID: 3-1.3.2:8
    chip-ID: 046d:082d
  Display: wayland server: Xwayland v: 24.1.5 compositor: kwin_wayland
    driver: gpu: nvidia,nvidia-nvswitch d-rect: 7680x4320 display-ID: 0
  Monitor-1: DP-1 pos: top-right model: MSI MPG321UX OLED res: 3840x2160
    hz: 240 dpi: 140 diag: 803mm (31.6")
  Monitor-2: DP-2 pos: bottom-l model: Dell U2723QE res: 3840x2160 hz: 60
    dpi: 163 diag: 685mm (27")
  API: EGL v: 1.5 platforms: device: 0 drv: nvidia gbm: drv: nvidia
    surfaceless: drv: nvidia wayland: drv: nvidia x11: drv: nvidia
  API: OpenGL v: 4.6.0 vendor: nvidia v: 565.77 glx-v: 1.4
    direct-render: yes renderer: NVIDIA GeForce RTX 4080 SUPER/PCIe/SSE2
    display-ID: :0.0
  API: Vulkan v: 1.4.304 surfaces: xcb,xlib,wayland device: 0
    type: discrete-gpu driver: N/A device-ID: 10de:2702 device: 1 type: cpu
    driver: N/A device-ID: 10005:0000
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor gpu: nvidia-settings,nvidia-smi
    wl: wayland-info x11: xdriinfo, xdpyinfo, xprop, xrandr

cat /etc/os-release
NAME="Fedora Linux"
VERSION="41 (KDE Plasma)"

uname -a
Linux xxx 6.12.15-200.fc41.x86_64 #1 SMP PREEMPT_DYNAMIC Tue Feb 18 15:24:05 UTC 2025 x86_64 GNU/Linux

echo $XDG_SESSION_TYPE
wayland

The system is an AMD 5950x, Nvidia 4080 Super, 128GB RAM.

2

I’ve managed to improve the situation slightly by adding ELECTRON_OZONE_PLATFORM_HINT=wayland to my environment file.

Works okay now:

  • Discord (glitchy startup logo but only issue so far)
  • Chrome (icon is generic wayland)
  • 1Password

Steam is still laggy, though it looks like it’s running xwayland. Spotify is crashing on startup without a trace so I need to investigate further.

It seems like xwayland is the culprit then. If every time I install something I have to find the magic incantation to get wayland running it’ll get frustrating.

Should xwayland be performing this poorly though?

3

Hi! Maybe double-check that the parameter to disable GSP firmware is being applied: nvidia-smi -q | grep GSP

Maybe try toggling triple buffering with KWIN_DRM_DISABLE_TRIPLE_BUFFERING=0 just in case?

Did you setup the KDE Spin from the ISO as a fresh installation, or installed on top of the GNOME-based Workstation?

4

Hi John,

GSP is definitely disabled. It was a fresh install from an ISO, so I’m running pretty stock standard.

I think I might’ve worked out the issue. I noticed in the games I started that the resolution was some bizarre value that was above 4K. The rendering was also a little blurry. I tried messing with the steam launch settings until I realised all games were wrong resolution.

KDE appears to have applied fractional scaling to both my monitors. One is 27” and the other is 32” so I assume there is some logic to make content look physically the same size. One monitor was 150% and the other 175%. That scaling factor seemed to be applied to the incorrect monitor in the game.

So, I made the fractional scaling the same value and my games ran at true 4K, rejoice.

But more importantly… xwayland apps run smooth as butter now. I could tell from the steam splash screen alone, because it has a spinner that has been lagging but is now smooth.

I’ve tested all my other apps and everything is fine. I reverted my Wayland force, and reinstalled a couple of apps I must’ve borked (Spotify, Signal).

So tldr if xwayland is lagging on KDE with Fedora 41… make sure your display scaling is set to the same value on both monitors!

5

Good catch on checking the scaling levels! X11, and by extension XWayland, don’t naturally play well with fractional scaling - especially not with mixed scaling levels across different screens - so I think you solved it there :slight_smile:

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