Laggy window animations at 3440x1440

Hello, I’m trying to dust off my then-stable Linux machine after about 1.5 years of no use, only to find that the desktop is extremely sluggish on my UWQHD 120 Hz monitor, especially resizing windows and scrolling. Changing the latency/quality value in the compositor has no effect. I tried Wayland but it only locked my monitor to 60 Hz without exposing any other display modes, made my nvidia-settings a lot simplified (I couldn’t even enable GSync) and all desktop animations seemed to be capped at 30 FPS or lower, so I switched back to X.

Tested with Manjaro KDE LiveCD as well, got same results with proprietary drivers, open source were slightly better but still not nearly as smooth as my Windows running on the same rig, and the screen turned black when I raised my screen to my native 120 Hz (100 Hz was the most that worked). And that still didn’t make all animations fast, especially GTK4 apps like Pamac were extremely slow or produced black banding inside the windows when I resized it. Turning off transparency effects on window move/resize didn’t help.

Is all this (considering my high-end gaming hw) normal for KDE or is there something I can try to make it snappier? I uninstalled and re-installed the drivers with sudo mhwd -a pci nonfree 0300, didn’t help.

GPU RTX 3090
RAM 64GB 3600 MHz
Primary monitor connected with DP, enabling built-in FPS meter always shows 120.

$ glxinfo | grep -i nvidia
server glx vendor string: NVIDIA Corporation
client glx vendor string: NVIDIA Corporation
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: NVIDIA GeForce RTX 3090/PCIe/SSE2
OpenGL core profile version string: 4.6.0 NVIDIA 545.29.06
OpenGL core profile shading language version string: 4.60 NVIDIA
OpenGL version string: 4.6.0 NVIDIA 545.29.06
OpenGL shading language version string: 4.60 NVIDIA
OpenGL ES profile version string: OpenGL ES 3.2 NVIDIA 545.29.06

A quick suggestion that may help for Pamac:

Use pacman to install/replace pamac-gtk4 with pamac-gtk3:

sudo pacman -S pamac-gtk3

You might find that less troublesome as an alternative.

For the rest, I have nothing much to add, except to ensure all updates are current, and issues resolved. Cheers.

Pamac is just one of them, Nautilus or Firefox or many other apps have slow redrawing animations as well, only pamac I think is the worst. I would like to know if this is normal for all people even with powerful hardware, and if only I’m affected, reinstalling older programs is not a solution I’m hoping for… I thought KDE is more optimised in resource management than Windows, which does window animations fine on the same PC.

Here is a video showing how the cursor is butter smooth, moving windows is sometimes slow, and resizing is the worst. I suspected G-Sync might be the issue as it lagged some animations on Windows as well, but toggling it in nvidia-settings and restarting didn’t make any difference. I recorded in 100 fps but Google player might downsample it, you have to download the video and play it locally to see the difference clearly.

Someone suggested I downgrade from 545 to 535, but I don’t know how to do that using mhwd, as I see only the newest one and 470 in it. I tried removing video-nvidia and installing all nvidia-535 packages in pamac, but that only got me to a black screen and I had to reinstall video-nvidia with mhwd

Yes, I understood that. Cheers.