https://bugs.kde.org/show_bug.cgi?id=497378
Bug ID: 497378
Summary: "Selection rectangle" on desktop lagging behind mouse
cursor, and very glitchy desktop icons when moved
Classification: Plasma
Product: plasmashell
Version: master
Platform: Debian stable
OS: Linux
Status: REPORTED
Severity: major
Priority: NOR
Component: generic-performance
Assignee: plasma-b...@kde.org
Reporter: sigmund.hay...@finestudio.org
Target Milestone: 1.0
Ever since switching to Linux and settling for KDE Plasma as the DE, I've
experienced two frustrating and persistent performance bugs on the desktop,
most likely closely related:
1. When clicking on the desktop and making a "selection rectangle", it very
noticeably "lags behind" the mouse cursor's position (in a smooth animation --
the actual drawing of the rectangle does not itself lag).
2. When moving icons around on the desktop, they are very "heavy", unresponsive
and glitchy. Unless I carefully place the mouse cursor over an icon, click and
then slowly move it to the new location, the mouse cursor and the icon get
"detached" from each other.
This happens even with a completely fresh installation, right away, with no
system load, on both Debian 12 (Plasma 5) and their "Debian Live" environment
which has Plasma 6 and updated drivers.
It has happened on two separate (powerful) PCs, with three different GPU
architectures: NVIDIA (earliest attempts), AMD and (the new one) Intel GPU.
The only way for me to be able to use the system at all is to run `kcmshell5
kcm_qtquicksettings` and switch the "Rendering backend" option from "Auto" to
"software" and reboot. If I do that, it's possible to use the desktop, but it's
still far from working correctly. The selection rectangle still isn't fully
following the mouse cursor even in this mode and the icons still act up in the
same manner randomly.
On both machines, all other parts of the Plasma GUI work correctly. Nothing
about the window management or applications menu etc. strikes me as being laggy
or glitchy. This issue seems fully contained to the "desktop" area, which
unfortunately is a "main workspace" for me and (I would assume) most other
users. I cannot understand how this is technically possible.
I have tried many things suggested by many people over an extended period of
time. Some fresh attempts from today:
* The note on https://wiki.debian.org/GraphicsCard#Intel which says to remove
the xserver-xorg-video-intel package doesn't help. The issue remains even after
doing that, turning the "Rendering backend" back to "Auto" and rebooting.
* Trying out Fedora-KDE-Live-x86_64-41-1.4.iso reveals that the selection
rectangle lag still happens on that different distro, although to a lesser
degree. The icons, however, seem much snappier/responsive here, so it does seem
to in some way be related to something that Debian does differently?
It's not an option for me to switch to a different Linux distro. I don't
understand how it can depend on the distro, when it's the same KDE Plasma
software and OS. It would be very interesting to learn what is causing this.
The new computer's CPU (with built-in GPU) is an Intel Core I9 14900. If that's
"too new" to be fully supported by Linux, it still doesn't explain how the same
problems happen on the 5+ year old HP workstation. I was prepared to believe
that the old one was simply broken somehow on a hardware level, until I
experienced the same issues on the new one.
Hopefully I've managed to include all relevant information.
--
You are receiving this mail because:
You are watching all bug changes.
