Okay, so, it seems the situation evolved meanwhile. I would like to express my warmest thank you to the Nvidia team as it was a major one.
One long standing and very annoying was apparently fixed, see : https://www.gamingonlinux.com/articles/nvidia-pushed-out-two-new-linux-drivers-recently-with-39645-and-39077.12184
“Fixed a bug that caused kwin OpenGL compositing to crash when launching certain OpenGL applications.”
I yet have to test in the long run but it seems the most annoying issue occuring with NVIDIA drivers & Kwin was fixed, that is to say : the panel / desktop freezing randomly when an app would interrupt and resume kwin compositing (they would still react to mouse clicks but wouldn’t update). It would be great if the NVIDIA team could get in touch with the kwin team (whose leader stepped down meanwhile) to tell them what was triggering it…
I still have the following problems with either no solution or requiring a work-around :
- sub-optimal framerate on the desktop (occurs under GNOME too, but doesn’t occur with open source drivers (Nouveau, AMDGPU, Intel…).
- work-around to get a tear-free experience (either : triple buffer ; GL_YIELD ; or force compositing pipeline). Not required either when using open source drivers. Also partly necessary under GNOME.
(also, applying “force compo pipeline” slows down a lot KDE startup, but maybe the problem is on KDE’s side this time !)
Cheers ! Thanks for caring for KDE users !