Kwin, NVIDIA, Plymouth - what is causing these graphics errors?

English Hardware
1

I am posting here because I am not sure where this should go. Not chit-chat for sure, since help IS needed.

Since doing a fresh install of openSUSE Leap 15.0 six weeks ago my system has become too unreliable to use for work. The symptoms are varied and the causes are not clear to me. I hope that, with feedback, I can gain more understanding.

This is a general purpose desktop PC:
openSUSE Leap 15.0 (fresh install, standard KDE, from DVD to dedicated SSD)
KDE Plasma Version: 5.12.6; KDE Frameworks Version: 5.45.0; Qt Version: 5.9.4
Kernel Version: 4.12.14-lp150.12.16-default
Processors: 8 x intel core i7-2600 CPU @3.40GHz; Memory: 7.8 GiB of RAM
Graphics: NVIDIA GF114 [GeForce GTX 560], with nvidia-gfxG04-kmp-default-390.87_k4.12.14_lp150.11-lp150.10.1
Hardware: nothing exotic. 8 years old ASUS motherboard. 10 years old Samsung 24E650 monitor (DVI) 1920x1200, 60Hz.

Symptoms (all these are intermittent, with no consistent link between actions and errors, sometimes everything works):
Distorted graphics, tearing, stretching, stuttering, etc.
Panel icons are unresponsive or, when clicked, show popups for, and open, other unrelated background processes.
KWin error messages - “Desktop effects were restarted due to a graphics reset”
Sometimes unable to log out, restart or shutdown from from GUI - attempt causes blank screen, unresponsive, reset to reboot.
“Random” system crashes occur, with blank screen (loss of work), cannot shut down, requires reset to reboot.

Remedial actions attempted:
Ran memcheck. Passed.
Checked all hardware connections. Passed.
Searched openSUSE forums, kde.org & web; found lots related, but nothing helpful. Tried a few suggested system settings changes - symptoms persist. Reverted most, but may have missed some. I did not edit any system files.
Deleted and reinstalled nvidia drivers, etc. - symptoms persist.
Deleted NVIDIA driver, system defaulting to nouveau (thanks) - fails to recognise monitor, defaults to 1600x1200.
Avoiding Firefox - symptoms persist.

I have KDE Neon on a spare partition, with nouveau. There are issues (not a distro) but it’s stable, so work goes on.

Thanks for reading. I am GMT +10. Please pardon slow responses.

2

I’ve seen a number of threads (across distros) describing similar behaviour. This nvidia thread may be of interest to you (apologies if you’re already aware of it)…

https://devtalk.nvidia.com/default/topic/1029568/linux/the-situation-on-kde-kwin-plasma-performance/1

If you read through to the end, it does appear that progress is being made but still not perfect yet. Anyway, hoping some of the suggestions made there may be help with improving your desktop experience a bit.

3

Thanks DF (@GMT+12), for this helpful response, and all your fine work here. A good read. It has been a bumpy journey from ye olde KDE3.
Seems there is progress. It’s great to see people being gracious. I’ll watch that threat for news. Phew, my system hasn’t crashed for 40 minutes.

4

This system has now been up for 48 hours without noticeable graphic errors. This is good.

KDE System settings > Display & Monitor > Compositor settings are:
Enable compositor on startup = unchecked
Scale method = crisp
Rendering backend = OpenGL 3.1
Tearing prevention “vsync” = Auto
Allow applications to block compositing = unchecked

Neither the openSUSE documentation nor the KDE The System Settings Handbook has been of much help to me in understanding these “Display & Monitor” issues. I don’t know enough to evaluate the diverse references and commentary thrown up by the google.

Where should I look to better understand these KDE “Display & Monitor” settings and hopefully keep this system relatively stable?

5

So you only tweaked the KDE settings? I was wondering if the advice given in the thread I linked to about setting GL_YIELD=USLEEP might be helpful…

or me, __GL_YIELD=USLEEP combined with enabling vsync in System Settings and in all games, plus “sync to vblank” in Nvidia settings seems to solve tearing and (almost all) stutter. For the remaining microstutter, which is seldom, it’s hard to say whether it comes from the game engine.

Where do you set __GL_YIELD=USLEEP? I did it in ~/.config/plasma-workspace/env/kwin.sh so I would be sure it’s early enough.

Neither the openSUSE documentation nor the KDE The System Settings Handbook has been of much help to me in understanding these “Display & Monitor” issues. I don’t know enough to evaluate the diverse references and commentary thrown up by the google.

Where should I look to better understand these KDE “Display & Monitor” settings and hopefully keep this system relatively stable?

Yes, the KDE Plasma 5 documentation that’s lacking in some areas. (No help for the compositor settings for example.) However, from what I’ve read, the KDE compositor settings are unlikely to help with screen tearing with respect to NVIDIA hardware.

FWIW, this thread has similar suggestions for setting the ‘__GL_YIELD’ environment variable…
https://forum.manjaro.org/t/screen-tearing-in-kde-with-nvidia-card/7956/12

Hopefully, others using NVIDIA graphics and proprietary drivers can chime in with their experiences and recommendations.

6

Thanks DF, your response is appreciated. I will keep investigating, but I am conscious that I have wasted forum members’ time posting this vague thread. I am grateful that nVidia builds useful graphics cards and provides ‘proprietary’ drivers for GNU/Linux systems that mostly work pretty well.

7

I’m happy to share what I’ve read, but not having this hardware means I can’t contribute technically as much as I’d like to. Don’t think of such a subject as wasting others time - that’s why people participate here to share knowledge and ideas, and assist where they can.