I previously experience a login loop with ubuntu 18.04 after installing nvidia driver. And now it is solved by adding “nogpumanager” kernal parameter and /etc/X11/xorg.conf file.
But after adding the xorg.conf file, I can not open nvidia setting.
When typing nvidia-settings, I got:
nvidia-settings ERROR: Unable to load info from any available system
You would have to create an xorg.conf which includes all nvidia gpus and adding screens for each. You could then use nvidia-settings in CLI mode using the --display option or the DISPLAY env variable.