Bug 507434

Summary:	When a desktop widget is animating the GPU usage is higher than the same widget placed in a Panel
Product:	[Plasma] plasmashell	Reporter:	Luis Bocanegra <luisbocanegra17b>
Component:	Containment	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED NOT A BUG
Severity:	normal	CC:	kde, notmart, serdarthtux
Priority:	NOR
Version First Reported In:	master
Target Milestone:	1.0
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	test widget to reproduce the bug

Description Luis Bocanegra 2025-07-24 08:47:54 UTC

Created attachment 183483 [details]
test widget to reproduce the bug

SUMMARY
When a widget that is constantly animating is placed on the Desktop, it uses more GPU compared to when placing the same widget inside a Panel

STEPS TO REPRODUCE
1.  Download the attached widget and install it
2. Place the widget in the panel and desktop
3. Use a software capable of monitoring the usage of the GPU used for rendering KWin/Plasmashell, refer to the output of `qdbus org.kde.KWin /KWin org.kde.KWin.supportInformation | grep -i '^opengl'`
4. Click on the test widget to toggle the BusyIndicator
5. Compare the GPU usage of each widget animating, one at a time

OBSERVED RESULT
When the desktop widget is animating the GPU usage is higher compared the usage of the same widget placed in the Panel

EXPECTED RESULT
Desktop widget should exhibit roughly the same GPU usage on both desktop and panel

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.4.80
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.1
Kernel Version: 6.15.7-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 12 × Intel® Core™ i7-9750H CPU @ 2.60GHz
Memory: 32 GiB of RAM (31.1 GiB usable)
Graphics Processor: Intel® UHD Graphics 630


ADDITIONAL INFORMATION
This was initially reported in a audio visualizer widget https://github.com/luisbocanegra/kurve/issues/40 and upon investigation it appears to affect any QML type displayed on the desktop widget as long as it is updating fast enough

Comment 1 David Edmundson 2025-07-24 09:54:49 UTC

>When a desktop widget is animating the GPU usage is higher than the same widget placed in a Panel(edit) 

When it's on the desktop, it has to re-render the desktop which is bigger than a panel and the entire wallpaper.

Performance is something we're always improving, but I don't think this ticket helps narrow that down.