Alt-Tab is very slow (> 1s) and freezes up the desktop

Help
1

I have a very slow response when switching tabs on my desktop. It’s a Fedora 40 KDE version, with KDE plasma 6.1.2.

The problem manifests itself when I alt-tab. For a quick task-switch, (brief alt-tab), there’s no problems, everything is quite fast. But when I actually want to see all my windows, it’s annoyingly slow - it takes between one and two seconds. And also when I release the alt-tab, the same happens, my entire system is frozen for about the same amount of time. The same happens with Alt-` (switch windows of the same app).

I’m 99% certain this is not my computer’s fault - I have Ryzen 9 7900x with 64GB of RAM, and an AMD Radeon RX6700XT card - these should be eating the stuff. And it generally does, just the tiny things like this one are sometimes glitchy.

Changing the Visualisation (in Task Switcher settings) does not solve the problem, even downloading new task switchers.

The searches online had lead me nowhere - switching themes (from Breeze or Fedora defaults) does nothing to help. I’ve read online things like adding TabBox → DelayTime to config (there’s no place in the UI to change this), but it also does nothing.

What could be the problem? Where could I be looking into it? How could I go about gathering more information, at least?

Why is my system freezing on the task switcher action?

2

If the issue goes away when you switch to the Large Icons visualization, then it’s probably 479250 – Brief screen freeze when opening Thumbnail Grid tabbox.

3

I also have this issue.
I’m using Arch Linux with KDE Plasma 6.1.3 with Ryzen 7 7840HS, 32GB RAM and RTX 2060.

4

I had the same problem (hiccup freeze on alt-tab, or when hovering on task bar and getting that preview show-up) for the past month, very disturbing.

I’m running an arch-based system, updated this morning (2024-09-05) (plasma-desktop 6.1.4-1), and the problems seems gone.

Hopefully it’s due to the update and not random tweaking I forget about.

5

By toggling off the “show selected window” under the task switcher settings worked for me.

KDE version 6.0.0
Plasma 6.0.3
Fedora 40

1 Like
6

Csaba’s solution worked well for me, as previously this caused heavy stuttering on my rather modern system and now it’s gone.

KDE Frameworks 6.7.0
KDE Plasma 6.2.2 on Wayland
Gentoo