mal@mal-desktop:~$ glxinfo | grep NVIDIA
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
Error: couldn't find RGB GLX visual
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
mal@mal-desktop:~$ sudo cat /etc/X11/xorg.conf | grep Driver
        Driver          "kbd"
        Driver          "mouse"
        Driver          "wacom"
        Driver          "wacom"
        Driver          "wacom"
        Driver          "nvidia"