[Desktop] Freezing/stuttering on desktop

[EinGans]

I am having an issue in the default KDE desktop where the interface will freeze momentarily, usually for less than 1000ms. When the video freezes, audio continues to play. It seems like mouse/kb inputs are still processed, but it's hard to be sure. The image on the screen stops updating.

I have noticed it sometimes happens in conjunction with disk activity - once I loaded the Telegram app, and it stuttered several times in a row concurrent to when each individual avatar image was loaded. Sometimes it happens when opening a Dolphin window with a large number of images/thumbnails. But it also happens during normal web browsing in Firefox.

Last year I used Kubuntu 24.04, which had the same issue, but much worse. It would be more like 5000ms freezes.
I dual boot with Windows 11 which doesn't have this issue. So I doubt it's hardware or BIOS related.

I'm thinking disk activity, maybe related to snaps? Or possibly nVidia drivers? I'm not sure how to troubleshoot from here.

Specs:

CPU: Ryzen 7 9700X
RAM: 32 GB DDR5-6000
GPU: Georce RTX 5070 Ti (nvidia-driver-595-open)
SSD: ADATA Legend 860 (NVMe)
Board: Gigabyte B650 Gaming X AX V2

[die.boer]

please post output of these 2 :

inxi -Gxx

echo $XDG_SESSION_TYPE

[Kabelbaum]

Bug

I think it is a common bug and affects me also. But it should be fixed in the upcoming kernel updates.

[EinGans]

goose@pyramid:~$ echo $XDG_SESSION_TYPE
wayland
goose@pyramid:~$ inxi -Gxx
Graphics:
Device-1: NVIDIA GB203 [GeForce RTX 5070 Ti] vendor: Micro-Star MSI
driver: nvidia v: 595.71.05 arch: Lovelace pcie:speed: 32 GT/s lanes: 16
ports:active: DP-3 empty: DP-1,DP-2,HDMI-A-1 bus-ID: 01:00.0
chip-ID: 10de:2c05
Display: wayland server: X.org v: 1.21.1.22 with: Xwayland v: 24.1.10
compositor: kwin_wayland driver:gpu: nv_platform,nvidia,nvidia-nvswitch
display-ID: 0
Monitor-1: DP-3 model: LG (GoldStar) ULTRAGEAR res: 2560x1440 hz: 144
dpi: 93 diag: 800mm (31.5")
API: EGL v: 1.5 platforms:device: 0 drv: nvidia device: 2 drv: swrast
gbm:drv: nvidia surfaceless:drv: nvidia wayland:drv: nvidia x11:
drv: nvidia inactive: device-1
API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 595.71.05
glx-v: 1.4 direct-render: yes renderer: NVIDIA GeForce RTX 5070 Ti/PCIe/SSE2
display-ID: :0.0
API: Vulkan v: 1.4.341 surfaces: N/A device: 0 type: discrete-gpu
driver: nvidia device-ID: 10de:2c05 device: 1 type: cpu
driver: mesa llvmpipe 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

[die.boer]

can you check whether this happens on X11 too?
check if it is installed with

apt policy plasma-workspace-x11

, if it is not you can install it with

sudo apt install plasma-workspace-x11

.
then at login choose plasma(x11) session

[Kabelbaum]

Maybe check the log also.
Stuff like apparmor="DENIED" can also cause lag I guess.

[boospy33]

I'm experiencing the same issue here with an AMD Radeon RX 7900 XT. But I'm still trying to figure out what's really causing it. Because sometimes it happens repeatedly throughout the day, and then other days it doesn't happen at all.

And the entire desktop definitely freezes for about half a second, because you can see the seconds on the clock ticking by very quickly.
This happens while browsing (not while watching videos) or in the console...

Bug

I think it is a common bug and affects me also. But it should be fixed in the upcoming kernel updates.

Thanks for the link. The interesting thing is that the bug didn't show up until the release. Everything worked great for a long time in the beta.

WORKAROUND = Disable SMT (AMD hyper-threading) into the bios fix the issue!!!

Great, half the power... 😅

[claydoh]

Or test the kernel patch using Proposed, before it is released to the general public. Note that installing this does not replace your current kernel, so you still have the other(s) as a boot option if it is not working properly for some reason.

[boospy33]

Or test the kernel patch using Proposed, before it is released to the general public. Note that installing this does not replace your current kernel, so you still have the other(s) as a boot option if it is not working properly for some reason.

But I don't quite understand how bug reports work (status). Because according to the status, the bug is still “Unassigned.” So technically, no one is working on it... Am I missing something here?

[claydoh]

You are not missing anything.

A status does not mean much, sometimes, especially if someone hasn't done the work, skipped it or something, especially as the fix may be part of that next kernel patch already, from a CVE/

Note that Timo Aaltonen and Mario Limonciello are Ubuntu and/or Canonical folks, at least one works on kernel stuff. Can't say why it might be physically assigned for this specific bug, or maybe it has been assigned elsewhere.



https://ubuntu.com/security/CVE-2026...0in%20progress

A package being in Proposed is the normal course for this type of thing.

[boospy33]

claydoh thanks for clarifying.