Could not open X display

root@localhost X11]# nvidia-settings --page=“X Screen0”
No protocol specified

** (nvidia-settings:23438): WARNING **: Could not open X display

ERROR: Unable to find display on any available system

After install nvidia proprietary driver 375.66 this error came((

root can’t use users x-server!
why you want to start nvidia-settings as root?
And if you really want it, do xhost + as user before.

Given you do this from a running x-session.

Don’t use “xhost +”, it allows anyone and everyone to connect to your X server!

You can either set the XAUTHORITY environment variable for the root shell to point at your user’s authority file, or do “xhost +si:localuser:root” to allow root to connect to the X server without the authority file.

If you’re using nvidia-settings to edit xorg.conf, I would recommend running it as a normal user, saving the new xorg.conf somewhere your user can write to, and then switching to root only to copy it to /etc/X11.

Not gonna work, still tearing on nvidia gtx 870m.

Not gonna work, still tearing on nvidia gtx 870m.