xrandr --prop
Screen 0: minimum 320 x 200, current 1680 x 1050, maximum 8192 x 8192
DFP1 disconnected (normal left inverted right x axis y axis)
	SignalFormat: DisplayPort
	ConnectorType: DisplayPort
DFP2 disconnected (normal left inverted right x axis y axis)
	SignalFormat: TMDS
	ConnectorType: HDMI
DFP3 connected primary 1680x1050+0+0 (normal left inverted right x axis y axis) 708mm x 398mm
	EDID:
		00ffffffffffff000000000000000000
		00110103800000780a0f50a555469924
		13494b23080081808140010101010101
		010101010101011d80d0721c1620102c
		2580c48e2100009e011d8018711c1620
		582c2500c48e2100009e000000fd0038
		551f500e000a202020202020000000fc
		004c4344204d543031450a202020012a
	SignalFormat: TMDS
	ConnectorType: DVI-I
   1680x1050     50.00*+  59.94    59.95
   1920x1080     50.00 +  60.00    50.00    59.94    60.00    59.94
   1776x1000     50.00    59.94    50.00    59.94
   1400x1050     50.00    59.94    59.95
   1600x900      50.00    59.94    59.95
   1280x1024     50.00    60.02
   1440x900      50.00    59.94    59.95
   1280x960      50.00    60.00
   1280x768      50.00    60.00
   1280x720      60.00    50.00    59.94
   1024x768      50.00    60.00
   1152x648      50.00    59.94
   800x600       50.00    60.32    56.25
   720x576       59.94    50.00    50.00
   720x480       50.00    60.00    60.00    59.94    59.94
   640x480       50.00    60.00    59.94
DFP4 disconnected (normal left inverted right x axis y axis)
	SignalFormat: TMDS
	ConnectorType: DVI-I
CRT1 disconnected (normal left inverted right x axis y axis)
	SignalFormat: VGA
	ConnectorType: DVI-I
CRT2 disconnected (normal left inverted right x axis y axis)
	SignalFormat: VGA
	ConnectorType: DVI-I