Graphics unplayably broken on new Linux computer

[Zaister]

I have a new machine on which I have installed Linux, just as on my previous machine. However, when I start up CK2, the graphics are completely broken, see the attached screenshots. In additoin to the broken look, the graphics are also excruciatingly slow. The video card is the same as previously (GeForce GTX 1070 Ti) and the CPU is an i7-8700K. I have tried uninstalling, deleting the local data directory and reinstalling the game, but that didn't help. There are no mods running and all DLCs are installed. Oh, and I get the same behavior with EU IV, too. What can I do so I can play the game again?

 

[Zaister]

OK, I got one stop further after some googling. It seems I needed to install the package libtxc_dxtn that i needed to render the map. That helps insofar as that the graphics now look normal. However, the game is still unplayably slow, even the interface or even the quit dialog takes several seconds to render. What am I missing?

 

[Zaister]

OK it seems this not after all CK2 related, other games show the same problem. Something else is missing in my installation. Please feel free to ignore me...

 

[Ujin]

@Zaister did you install a proprietary video driver?

 

[Zaister]

Yes, I'm using the proprietary Nvidia driver, but it turns out I had not configured OpenGL to actually use that driver, so everything was on software rendering. Everything is good now.