$ xrandr
Screen 0: minimum 320 x 200, current 5120 x 1600, maximum 16384 x 16384
DFP1 disconnected (normal left inverted right x axis y axis)
.....
DFP6 connected primary 2560x1440+2560+160 (normal left inverted right x axis y axis) 596mm x 335mm
   2560x1440      60.0*+
   1856x1392      60.0  
   1792x1344      60.0  
   1920x1200      60.0  
   .....
   640x480        66.6     59.9  
DFP7 connected 2560x1600+0+0 (normal left inverted right x axis y axis) 641mm x 401mm
   2560x1600      60.0*+
   2048x1536      60.0  
   .....
   640x480        59.9  
CRT1 disconnected (normal left inverted right x axis y axis)