How to switch from nvidia to nouveau drivers on ubuntu 18.04

Solution 1:

You can switch drivers by running the GUI Additional Drivers from the Software and Update app.

Or you can do it from the terminal commandline by running these commands:

$ ubuntu-drivers devices

This will show you your available drivers. Then pick the nouveau driver found and switch to it with this command:

$ sudo apt install [xserver-xorg-video-nouveau]

The [xserver-xorg-video-nouveau] is an example a nouveau driver that might be found.

If for some reason you have removed your nouveau drivers, you can reinstall them with (for example):

$ sudo apt install nouveau-firmware

You can verify the available nouveau drivers from the repository with this command:

$ apt search nouveau

Solution 2:

Run

sudo apt purge nvidia-driver-390
sudo apt autoremove

and reboot.

Another way is to do it in "Software & Updates" -> Additional Drivers tab.

Solution 3:

Answer my own question: ubuntu-drivers and "Software and Update > Additional drivers" are broken on ubuntu 18.04. We'll have to wait until developers fix it. For now just use the proprietary nvidia driver which works ok.