SUMMARY When using Wayland with the Nvidia proprietary driver, all non-Qt/KDE apps stutter to a point that makes them unusable. This is extremely visible when the application does some playback (like playing a video in Firefox) or typing something in a box (like the Matrix chat Element). It seems that instead of rendering the next frame, for a split second the previous frame is being rendered and only then the correct frame is being drawn. For example, if you have in a text box the word "hell", when you type the last "o", sometimes, the word drawn will be "hel" and only a bit afterwards you will see the full "hello" word. STEPS TO REPRODUCE 1. Start a Wayland session with the Nvidia proprietary driver. 2. Start any type of non-Qt/KDE application (like Element chat). 3. Type a message. OBSERVED RESULT The rendered frames are not sequential. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Plasma master (Wayland session) KDE Plasma Version: 5.23.90 master KDE Frameworks Version: 5.91 master Qt Version: 5.15.2 Video Driver: nvidia 495.46, egl-wayland 2:1.1.9-master, xorg-xwayland master 21.1.2.901.r270
Created attachment 146091 [details] The video playback rendering is not sequential. The video used in the clip: https://www.youtube.com/watch?v=cWmURg_rM2o&t=7s Note: The same video plays correctly under X11.
I'll throw my hat in the ring and mention this is still a problem in the 5.25 beta. Scrolling in Firefox in a wayland session is an easy reproduction step. Confirmed on two separate machines (GTX 970 and GTX 2080 Super, multi-monitor respectively), same exact behavior. plasmashell: 5.24.90 KDE Frameworks: 5.94.0 Qt: 5.15.4 Nvidia: 515.43.04 xwayland: 22.1.2
Note by "still a problem in" I don't necessarily mean "still a problem with". This may very well be upstream. :)
Problems with xwayland and Nvidia are known.