Bug 483698

Summary: choppy framerate in X11 after upgrade to Plasma 6
Product: [Plasma] kwin Reporter: S. Christian Collins <s_chriscollins>
Component: performanceAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: kde, nate, xaver.hugl
Priority: NOR Keywords: qt6, regression
Version: 6.0.2   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed In: 6.1.1
Sentry Crash Report:
Attachments: additional information from Info Center

Description S. Christian Collins 2024-03-15 17:36:47 UTC 
Created attachment 167280 [details]
additional information from Info Center

SUMMARY
Since upgrading my laptop to Plasma 6, the compositor performance in X11 has become very choppy. I previously had smooth 60 fps for desktop effects, but now I get around 32-35 fps when moving a window around and 45-50 fps when doing nothing. Switching to Wayland, everything stays at a smooth 60 fps.

Here is a video comparing X11 vs. Wayland performance on my laptop: https://youtu.be/O5LSSBpYJW0

SOFTWARE/OS VERSIONS
Linux: KDE neon 6.0 User Edition
KDE Plasma Version: 6.0.2
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2

LAPTOP INFO
PC: HP Pavilion m6-1035dx
CPU/GPU: AMD A10-4600M 2.3 GHz quad-core APU with Trinity [Radeon HD 7660G] Graphics (using radeon driver)
RAM: 8GB DDR3 (2x 4GB PC3-12800 1600 MHz), 7.2GB usable

ADDITIONAL INFORMATION
I have attached additional system information from Info Center. I also use the following X11 settings for my GPU, though deleting this file appears to make no difference to performance:
---
Section "Device"
    Identifier "Card0"
    Driver "radeon"
    Option "AccelMethod" "glamor"
    Option "TearFree" "off"
    Option "DRI3" "1"
EndSection
---
Comment 1 S. Christian Collins 2024-03-15 18:31:27 UTC 
Testing with the KWIN_X11_NO_SYNC_TO_VBLANK=1 environment variable set, I am now getting well over 60 FPS constantly, so my issue would seem to be possibly vsync related.
Comment 2 S. Christian Collins 2024-03-15 18:46:09 UTC 
I also tested the following environment variables found in other framerate-related bug reports, but neither of them had any affect in my case:
---
KWIN_DRM_DISABLE_BUFFER_READABILITY_CHECKS=1
KWIN_DRM_NO_AMS=1
Comment 3 Zamundaaa 2024-06-09 16:50:59 UTC 
Please attach the output of
> glxinfo | grep timer_query
Comment 4 S. Christian Collins 2024-06-10 19:23:06 UTC 
(In reply to Zamundaaa from comment #3)
> Please attach the output of
> > glxinfo | grep timer_query

    GL_ARB_texture_view, GL_ARB_timer_query, GL_ARB_transform_feedback2, 
    GL_EXT_texture_swizzle, GL_EXT_timer_query, GL_EXT_transform_feedback, 
    GL_ARB_texture_swizzle, GL_ARB_texture_view, GL_ARB_timer_query, 
    GL_EXT_texture_snorm, GL_EXT_texture_swizzle, GL_EXT_timer_query, 
    GL_EXT_discard_framebuffer, GL_EXT_disjoint_timer_query,
Comment 5 Bug Janitor Service 2024-06-25 03:47:30 UTC 
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 6 Zamundaaa 2024-06-25 12:07:14 UTC 
Okay, so the OpenGL extensions KWin uses for render time tracking are supported... 6.1.1 will contain some code that helps debug this sort of thing.
Could you check if the problem is still there with 6.1, and if it is, run 6.1.1 with the KWIN_LOG_PERFORMANCE_DATA=1 environment variable set, and upload the performance logs KWin saves in your home folder?
Comment 7 S. Christian Collins 2024-06-26 14:13:27 UTC 
This issue is now resolved in Plasma 6.1.1. I am now getting smooth desktop response in Plasma again. Thank you!