switch between nvidia and intel gpu without reboot

Question

So, I was able to switch from nvidia to intel and back using nvidia-prime on my system (Ubuntu 17.10) - just logout and login again - but now it seems to require a reboot between switches (If I just logout, I can't login again, it just returns to the login screen in an infinite loop).

I wonder what has changed, and how I can get the original behavior back?

I'm using the 390 nvidia driver (it happens also on the 384, on which I'm pretty sure it worked properly a few months ago).

Solution

Seems like GDM3 was the culprit, changed to lightDM and now it works perfectly.

From reading on this subject, I figured out that prime-switch 0.8.8 (the one used in Ubuntu 18.04) requires a full restart, while 0.8.5 (used in 17.10) works with just login\logout with lightDM.

An unofficial workaround for 18.04 is available here

Comments

[Daniele Dellafiore]

you should vote / follow this bug: bugs.launchpad.net/ubuntu/+source/nvidia-prime/+bug/1765888

[Mamrezo]

For me, there is no difference between full restart OR login\logout they are jus as same when I need to close all files/IDE/Browser/running CLI command as a web developer...