240hz feel like 30 on 2 Displays Setup in Ubuntu 24.04 with RTX 4070

Graphics / Linux Linux
1

Hello,

recently i switched from Windows 11 to Ubuntu 24.04 for Developing Purposes (PHP and so on).
My Setup is:

  • Desktop PC, no Laptop
  • AMD Ryzen 7 7800X3D
  • 32GB Ram
  • RTX 4070
  • Main Screen: Samsung Odyssey G9 with 5120x1440 @ 240 Hz
  • Second Screen: LG with 2560x2880 @ 60Hz

Now the Problem is, everything feels like 60hz, moving windows feels really laggy.
After some Research i found out that it can happen with the Ubuntu Compositor that has some Problems when one Screen is at 60hz and you should use Wayland. Tryed that, but wayland keeps crashing, so also no the solution.

Try:
X Server Display Configuration to be set at 240hz as Primary Screen, with Force Composition Pipeline and Full Force Composition Pipeline, but that also didnt help.

My Nvidia Bug Report:
Processing: nvidia-bug-report.log.gz…

I hope someone can help me to fix the Issue without switching away from Gnome, i like it how it is, except for my Problem.

2

Yeah, it’s because X11 can’t handle 2 screens with different refresh rates. It defaults to the lowest refresh rate.
That’s why you should use wayland.
There’s a hack for KDE that lets you use 240hz “fake” refresh rate with X11 which makes the experience a bit better. I don’t know about Gnome tho’.

For reference, here’s how you do it with KDE, put this in /etc/environment:

KWIN_X11_REFRESH_RATE=240000
KWIN_X11_NO_SYNC_TO_VBLANK=1
KWIN_X11_FORCE_SOFTWARE_VSYNC=1
3

Well i dont want to switch to KDE, it just feels wrong to me after using Gnome for what feels líke forever :D
And wayland has problems sadly, it boots and shows but when i try to open the settings for example they just crash every time.
Also i had kubuntu for a day before and i had the same problem.