desktop@steamos:/var/log$ DISPLAY=:1 xrandr --prop
Screen 0: minimum 8 x 8, current 3840 x 2160, maximum 32767 x 32767
DP1 disconnected (normal left inverted right x axis y axis)
	Broadcast RGB: Automatic
		supported: Automatic, Full, Limited 16:235
	audio: auto
		supported: force-dvi, off, auto, on
DP2 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 1600mm x 900mm
	EDID:
		00ffffffffffff0011ee460001010101
		0019010380a05a780aee91a3544c9926
		0f5054a1080031404540614071408180
		01010101010108e80030f2705a80b058
		8a0040846300001e023a801871382d40
		582c450040846300001e000000fc0044
		454e4f4e2d4156520a202020000000fd
		003a3e1e883c000a202020202020013b
		020360f158109f041305140302122021
		22150160615d5e5f6566626364293d06
		c0150750095707830100007f030c0025
		00b83c20c0910102030401410e3c0810
		181006101610281066680067d85dc401
		788003e305c000e40f00c018e3060701
		023a801871382d40582c4500c48e2100
		001e000000000000000000000000005d
	_MUTTER_PRESENTATION_OUTPUT: 0
	Broadcast RGB: Automatic
		supported: Automatic, Full, Limited 16:235
	audio: auto
		supported: force-dvi, off, auto, on
   3840x2160     60.00*+  30.00    25.00    24.00    29.97    23.98
   4096x2160     24.00    23.98
   1920x1080     60.00    50.00    59.94    30.00    25.00    24.00    29.97    23.98
   1920x1080i    60.00    50.00    59.94
   1280x1024     60.02
   1152x864      59.97
   1280x720      60.00    50.00    59.94
   1024x768      60.00
   800x600       60.32
   720x576       50.00
   720x480       60.00    59.94
   640x480       60.00    59.94
   720x400       70.08
HDMI1 disconnected (normal left inverted right x axis y axis)
	aspect ratio: Automatic
		supported: Automatic, 4:3, 16:9
	Broadcast RGB: Automatic
		supported: Automatic, Full, Limited 16:235
	audio: auto
		supported: force-dvi, off, auto, on
HDMI2 disconnected (normal left inverted right x axis y axis)
	aspect ratio: Automatic
		supported: Automatic, 4:3, 16:9
	Broadcast RGB: Automatic
		supported: Automatic, Full, Limited 16:235
	audio: auto
		supported: force-dvi, off, auto, on
HDMI3 disconnected (normal left inverted right x axis y axis)
	aspect ratio: Automatic
		supported: Automatic, 4:3, 16:9
	Broadcast RGB: Automatic
		supported: Automatic, Full, Limited 16:235
	audio: auto
		supported: force-dvi, off, auto, on
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
desktop@steamos:/var/log$
desktop@steamos:/var/log$
desktop@steamos:/var/log$
desktop@steamos:/var/log$
desktop@steamos:/var/log$
desktop@steamos:/var/log$ uname -a
Linux steamos 4.5.0-997-generic #201603142201 SMP Tue Mar 15 02:03:35 UTC 2016 x86_64 GNU/Linux