I just upgraded to Ubuntu 15.10 and switched from Bumblebee to Nvidia Prime. I'm currently using the 355.11 driver from https://launchpad.net/~graphics-drivers/+archive/ubuntu/ppa, but the problem also occurs when using the drivers in the official Ubuntu repo.
Prime works as expected, apart from the fact that I need to reboot in order for it to switch cards. If I logout and try to login again after switching, it just keeps showing me the login screen after I type in my password. This happens regardless of whether I switch from Nvidia to Intel or from Intel to NVidia.
Here's my /var/log/Xorg.0.log after I switch from Nvidia to Intel and try to login: http://termbin.com/n75a
When I go to TTY1 and do "prime-select nvidia" (the driver that was loaded during boot), I can login again at TTY7.
This question seems similar to ubuntu 14.04 – nvidia prime only works on restart (logout-login doesnt work), but the only answer there is to install Bumblebee…
Does anyone have an idea on how to solve this?
Best Answer
Why did you switch from bumblebee to PRIME???!!!! Is there a serious reason? For me PRIME gives me nothing but problems, screen tearing all over the place and no Vsync in games!!!
I strongly recommend you switch to bumblebee with the nvidia-355, works like a charm for me and many others!!