Making peace: Nvidia and KDE Plasma Wayland

[Bink]

Nvidia and KDE Plasma running under Wayland is a bit hit and miss. Sometimes it’s fine (such as on an older gaming system I have), but on one of my systems in particular, I’d been wrestling with it for months, without success.

This week however, I may have finally put my finger on the settings that have made a critical difference, in my case at least. I wanted to share those here, in case it might be helpful to anyone else with similar ongoing issues.

This is assuming you’ve already done the typical Nvidia + Wayland steps, enabling modeset and fbdev, so I won’t detail those here.

1. Stuttering issues:
   Disable VRR (variable refresh rate) / adaptive sync. Disabling this in the monitors built-in settings seems to also remove the option from Plasma’s display configuration, which is how I achieved this.

2. Window sizing issues:
   “Floating panels” is enabled by default (may be theme specific), but can cause issues for Nvidia GPU’s. To disable it, right-click on your start-bar and Show Panel Configuration, and make sure the “Floating panels” slider is disabled. If enabled, it might even give you a warning about this issue!
   

   

3. LibreOffice scaling issues:
   The UI of LibreOffice might appear tiny or huge on different screens. This is a known issue when running multiple displays with different scaling settings. To fix this, add this as an environment variable for your LibreOffice shortcuts:

WAYLAND_DISPLAY=libreoffice

4. Wayland hinting:
   Previously, I had enabled hints for electron apps and Chromium based browsers, but disabling “Floating panels” (#2) has so far resolved those issues with electron and Chromium derivatives and I no longer use these settings.

5. Firefox derivative glitches:
   LibreWolf often visually glitches becoming completely unusable and the desktop as a whole would start to feel broken. See #6 for fix.

6. Excessive VRAM consumption:
   (note, after a July 2025 update, using the Software rendering backend results in a crashing desktop. See here and here.)
   I noted that the /usr/bin/plasmashell process was consuming 3/4 of my GPU’s VRAM (12GB of 16GB) causing render failures in Blender and DaVinci Resolve Studio. One cause of this is using Plasma’s slideshow wallpaper feature. Every time the slideshow cycles, additional GPU memory is taken by plasmashell. This is on a per-display basis, so the issue compounds with multi-display setups. Both this issue, and #5 above were resolved by setting the Rendering Backend to Software in the Plasma Renderer settings, however, note recent (July 2025) issues with enabling this.
   

   

And that’s it for now. I’m still having some issues with regards to colour calibration and display profiles lacking tonal range and appearing washed out under Wayland.

[manuel]

Thanks for the tips! I’ll try them as soon as possible.

Here one annoying issue has been using the USB TV stick with kaffeine. On x11 it works flawlessly (that’s why I’m using x11), but on wayland it has an issue with starting the kaffeine window, and then after a few seconds kaffeine crashes.
Any ideas for that?

[Bink]

I installed and ran kaffeine under Wayland (Plasma) and so far I haven’t been able to reproduce an issue, playing local 4K videos and streaming audio.

Running it from command line may produce a useful error?

kaffeine

I’m not sure if this will help, but you could also try forcing it to use the X11 platform plugin on launch. There’s two ways:

1. Using kaffeine’s own command option:

kaffeine --platform xcb

2. Defining an environment variable on launch:

QT_QPA_PLATFORM=xcb kaffeine

As a note, the current release of kaffeine uses Qt5, but Qt6 support has been committed and is scheduled to be included in kaffeine 2.1.0, so one hopes better Wayland support will come as a result.

[manuel]

Thanks! I’ll try those ideas.

[manuel]

Thanks! Command kaffeine --platform xcb did the trick.

I remember trying this when I started experimenting with Plasma wayland quite a long time ago, but that experiment failed. Either something has changed/fixed, or I did something else wrong when trying xcb. Or both…

Anyway, now wayland is working for me better than ever before!

And sorry for the delay in answering to your suggestions.

[Bink]

Added “5. Firefox derivative glitches and VRAM consumption”, a reference to:

Plasma VRAM usage

I’m frequently using DaVinci Resolve Studio and Blender for various tasks (but not simultaneously). I have a decently powerful Nvidia RTX A4000 16GB GPU, yet in both of these programs have at various occasions hit out of memory errors, specifically VRAM memory (my system has 64GB RAM). Today, I decided to do a little digging into this, because on one Blender project, the numbers just weren’t adding up, with it failing out at a mere fraction of my total VRAM. A quick search and I read about th…

[Bink]

Discussion in this thread with @cscs prompted me to investigate the cause of plasmashell’s excessive GPU memory consumption under Wayland. Using this command I could see my GPU’s memory consumption near real-time:

nvidia-smi -l 1

I was seeing the GPU memory jump-increase roughly 2 times a minute, and quickly realised it was happening when my slideshow wallpapers cycled every minute! It’s per-display too, so additional displays multiply the issue. Over the course of a day, that adds up! I changed the cycle interval to 2 seconds and sure enough, GPU memory was getting chewed up.

Investigating the issue online revealed long standing memory issues under Plasma with slideshow wallpapers, dating back years, so I’m not pinning my hopes on a fix at the moment. For now the options are:

1. Stop using slideshow wallpapers, or reduce the cycle interval so the issue is slower.
2. As needed, restart plasmashell, which will free up the GPU memory:

plasmashell --restart &