xrandr
wants to know which output port you want to apply the new modeline to. Most modern graphics hardware supports more than one output port, for example an HDMI port plus a VGA port on a graphics hard or an internal LCD screen plus an external port on a laptop.
Run xrandr
without any arguments to see a list of available outputs. The names of the outputs are usually of the form VGA1
or LVDS1
. This will also tell you whether or not each output is connected and what its resolution and available modelines currently are.
It might be helpful to add that this is usually of the form ‘VGA1’ or ‘LVDS1’ etc. – Claudius – 2012-11-03T13:35:12.640
@Claudius good idea. I've added that. Also, please feel free to edit answers yourself if you have something useful to add! – Celada – 2012-11-03T14:04:58.027