So I had my usual problem with screen tearing on Ubuntu 19.10 but instead of my usual switching to Metacity + Compton I wanted to try using Gnome Shell. However Gnome shell doesn’t support replacing the compositor.

First step is to allow the NVidia driver to support kernel mode setting:

sudo nano /etc/modprobe.d/zz-nvidia-modeset.conf

Adding

options nvidia-drm modeset=1

And then

sudo update-initramfs -u

Check with

sudo cat /sys/module/nvidia_drm/parameters/modeset

Then add a startup application

xrandr --output eDP-1-1 --set 'PRIME Synchronization' '1'

Finally switch from gdm3 to lightdm.

sudo apt install lightdm

This fixed the following issues:

• Vulkan need me to run sudo vulkaninfo before launching a game
• Suspend / Resume were not working
• External displays didn’t always work
• Nicer login screen!