Switching between Intel and Nvidia graphics cards on an Optimus laptop with Leap 15.3

At my present location an old laptop with an Optimus system still provides me with good services. Recently, I installed Opensuse Leap 15.3 on it. Since then I have tried almost all I can think of to get Bumblebee running smoothly on it. In the end I gave up – sometimes “primusrun” worked, sometimes not – especially with more complex applications like Blender. And even if “primusrun” worked – “optirun” most often did not.

So, I had a look at “prime-select” installed by the packet “suse-prime” of Opensuse. Again I had mixed experiences: This worked sometimes from the command line and sometimes not. There were multiple things which were somehow interwoven:

  • bbswitch intervened or was used by prime-select when switching to Intel – and when it did and turned the nvidia card off, you could activate it again, but afterward the Nvidia device it was not recognized by the native Nvida driver or by prime-select. Most often I had to reboot.<
  • When I was lucky and after reboots got a configuration where the Nvidia driver was loaded in parallel to the i915 for Intel and used “prime-select” together with an init 3 / init 5 sequence the display manager sddm did not come up. Others had this problem, too.
  • To switch between the graphics cards it was absolutely necessary to login into my graphical KDE desktop, use a root terminal and switch to the Nvidia card with prime-select from there. Then I had to log out and if I was lucky the display manager came up and the Nvidia card was really active.

But do not ask me, what I had to do in which order to get the aspired result. All in all the behavior of “prime-select” was a bit unpredictable. Then after updating a lot of packets yesterday I could no longer get prime-select to do the right things any more. Most often I got the message:

ERROR: Unable to query GPU information

Or : No such device found.

Solution Part 1: Deinstallation of unrequired RPMs and reinstallation of required RPMs

In the end I deinstalled Bumblebee (as recommended by posts in Suse forums) and also bbswitch. Afterward I reinstalled the packets “suse-prime” and “plasma5-applet-suse-prime” from the Leap 15.3 Update-repository (i.e. the Update repo for the Enterprise system) and the Nvidia-drivers from Opensuse’s Nvidia repository. I rebooted and my “sddm” display-manager came up – with the Intel driver active – but the Nvidia driver was loaded already nevertheless. Checked with lsmod.

Later, I found that all files in “/etc/prime” had been rewritten. I suspect that I had something in there which was no longer compatible with the latest drivers and prime-versions. In addition the file “90-nvidia.conf” has been replaced in “/etc/X11/xorg.conf.d“.

Solution Part 2: Use the “Suse Prime Selector” applet!

Then I used the applet in the KDE Plasma desktop to switch to Nvidia. This seemed to work and led to no errors. I just had to log out of my KDE Plasma session and in again to work with KDE on a running Nvidia card. (Ignore the message that you have to reboot).
Afterward I also tested switching by using the command “prime-select” as root in a terminal window of the KDE desktop. Worked perfectly, too.

Conclusion

I am not sure what the ultimate reason was to get prime-select running. The deinstallation of Bumblebee and bbswitch? The new Prime and Nvidia configuration files? Or a new udev during other updates?

Anyway – using the Suse Prime Selector applet or just using the command “prime-select” as root in a terminal window inside KDE Plasma has become a very stable way on my Leap 15.3 laptop with KDE to switch between graphics cards reliably. I still have to log in and log out again of the KDE session – but so far I have never experienced any problems with the display-manager again.

Just for information: I am using the following Nvidia drivers packages:

The prime-select packet version is:

Links

https://www.reddit.com/ r/openSUSE/comments/ib9buv/ opensuse_kde_suse_prime_selector_applet_for/
https://forums.developer.nvidia.com/t/kubuntu-18-04-gives-black-screen-when-sddm-starts-no-login/61034/11
https://wiki.archlinux.org/title/PRIME# Configure_applications_%20 to_render_using_GPU
https://www.opensuse-forum.de/thread/63871-suse-prime-error-unable-to-query-gpu-information/
https://opensuse.github.io/openSUSE-docs-revamped-temp/hybrid_graphics/

Ceterum censeo: The worst living fascist and war criminal today who must be isolated, denazified and imprisoned is the Putler.