Bug 515571 - Sluggish response time with mixed refresh rates
Summary: Sluggish response time with mixed refresh rates
Status: REPORTED
Alias: None
Product: krita
Classification: Applications
Component: * Unknown (other bugs)
Version First Reported In: 6.0.0-beta1
Platform: Kubuntu Linux
: NOR normal
Target Milestone: ---
Assignee: Krita Bugs
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2026-02-05 20:13 UTC by stuff
Modified: 2026-02-05 20:13 UTC (History)
0 users

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
latency comparison video (361.42 KB, video/webm)
2026-02-05 20:13 UTC, stuff
Details

Note You need to log in before you can comment on or make changes to this bug.
Description stuff 2026-02-05 20:13:52 UTC
Created attachment 189252 [details]
latency comparison video

SUMMARY

Krita 6 has a significantly higher latency by default for me compared to Krita 5.

My primary monitor is 144Hz, my others are 60Hz. When krita is on a 60hz monitor it's very sluggish, but on the 144Hz monitor it's fine.

Using the vblank_mode=0 env variable alleviates the lagginess on the 60hz monitors.
Changing my primary monitor's refresh rate down to 60hz also seems to fix it instantly, even while Krita is running. (see attachment for a video taken on my 60hz monitor, showing the panning latency before and after adjusting the other monitor's refresh rate)

Happens both with and without Canvas Graphics Acceleration checked.

STEPS TO REPRODUCE
1. Have too multiple monitors with different refresh rates
2. Run krita 6.0 on one of the lower hz ones
3. I assume wayland is also important?

OBSERVED RESULT
program repainting seems very slow and lags far behind

EXPECTED RESULT
no laggier than krita 5 in the same scenario

SOFTWARE/OS VERSIONS
$ kinfo
Operating System: Kubuntu 25.10
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.2
Kernel Version: 6.17.0-8-generic (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-6700 CPU @ 3.40GHz
Memory: 32 GiB of RAM (31.3 GiB usable)
Graphics Processor: AMD Radeon RX 6600

ADDITIONAL INFORMATION