xrandr

Without external VGA: > xrandr Screen 0: minimum 320 x 200, current 1280 x 800, maximum 3840 x 1200 VGA disconnected (normal left inverted right x axis y axis) LVDS connected 1280x800+0+0 (normal left inverted right x axis y axis) 331mm x 207mm 1280x800 60.0*+ 60.0 58.9 1024x768 60.0 800x600 60.3 56.2 640x480 59.9 TV disconnected (normal left inverted right x axis y axis) With VGA in mirror mode: > xrandr Screen 0: minimum 320 x 200, current 1280 x 800, maximum 3840 x 1200 VGA connected 1280x800+0+0 (normal left inverted right x axis y axis) 376mm x 301mm 1280x800 60.0*+ 58.9 1280x960 60.0 60.0 1024x768 60.0 800x600 60.3 56.2 640x480 60.0 59.9 LVDS connected 1280x800+0+0 (normal left inverted right x axis y axis) 331mm x 207mm 1280x800 60.0*+ 60.0 58.9 1024x768 60.0 800x600 60.3 56.2 640x480 59.9 TV disconnected (normal left inverted right x axis y axis)