Hi,
for past few days I am trying to mitigate video playback stuttering when opening new windows either Konsole or Dolphin, interacting with plasmashell like system try or application launcher. On my main system I'm running nvidia with proprietary driver, but I was able to find to some degree the behavior on laptop with Interl iGpu. Now, I get that the best solution for this is just not do that, if I already have butter smooth playback, which was also kind of pain to setup.

But there is reason, why I need this: as a projectionits in cinema and occasional event streamer I rely on the ability to work with resources behind the scene - that means opening files, terminals, using multiple workspaces. And that is the problem: if you have video running on secondary display, you don't want some hiccups because of you opening htop on the primary screen. Second problem is OBS: as I understand there is videorendering done with opengl and if I open window or resize obs window even, it is rendered into the final video, not only just preview.

Activating nvidia OSD with env variable I was able to trace the problem a bit from my limited understanding and wheres it is usually looked for in kwin, I found that I was not able to disable vblank in plasmashell itself: even if nvidia OSD was activated in the same file (/etc/profile; which incidentally is read only by gdm3 and not by lightdm, just to mention that). So switching to software rendering on plasmashell helped a ton and even compositor can run opengl3.1 instead of xrender (kwin still needs fps setuped higher that displays refresh rate cause of vsync)! But there is still some glitch. Running FPS indicator (which is not a benchmark) I can see spikes in (presumably) opengl use and alse red or black line, that correspond to the action.

Now, my question is, if is there something else, that might need switching to eliminate it completely? If this is known issue, if I should test something else? If I can help with anything to resolve this?

I might add: the same issue was tested by me on Debian Sid (my main OS), Pop_Os! and Manjaro. The software render was tested only on Debian, cause I broke the other two meanwhile ( ). I will try to fix them and give them a try and I expect Manjaro to be the most usable, cause it was actully out of the box much responsive then Debian or Pop_Os!, but that also could be the theme (maybe?). And Gnome3 faired bit worse, I might add - this issue seems to plague most of the DE, but I did not test it rigidly yet.

Thanks for helping and reading this far! Best
jaromir


little update:
software composing on plasmashell makes stutters with resizing windows. so there's that