I've found a workaround for my issue temporarily using the --fbmm switch in xrandr: bernie@vicious:~$ DISPLAY=:0 xdpyinfo | grep dimensions dimensions: 1024x768 pixels (270x203 millimeters) bernie@vicious:~$ DISPLAY=:0 xrandr --fbmm 708x398 bernie@vicious:~$ DISPLAY=:0 xdpyinfo | grep dimensions dimensions: 1024x768 pixels (708x398 millimeters) Regards, Bernie