[SOLVED] Identifying a monitor on a multi monitor setup

sycamorex · 11-13-2011, 11:29 AM

I'm using the nVidia binary driver (TwinView). When I type xrandr --current, I get:

Code:

xrandr: Failed to get size of gamma for output default
Screen 0: minimum 3840 x 1200, current 3840 x 1200, maximum 3840 x 1200
default connected 3840x1200+0+0 0mm x 0mm
   3840x1200      50.0*

I'd like to identify my monitors as in:

Code:

Screen 0: minimum 320 x 200, current 2560 x 1024, maximum 8192 x 8192
VGA1 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm x 270mm
.....
LVDS1 connected 1280x800+1280+0 (normal left inverted right x axis y axis) 261mm x 163mm
.....

I changed the nvidia-settings to Separate X window to see if it'll make any difference, but then only one monitor seems recognised so I reverted to TwinView.

See the nvidia-settings in the attached screenshot. Are my displays DFP-0 and DFP-1?

Thank you

jamesf · 11-13-2011, 02:43 PM

Yes, they are. To make sure just enter 'xrandr' from a shell prompt and it will dump what X sees.

When you had two different screens set up you should have specified -display to xrandr, like mine:

Code:

james@gaz:~$ xrandr -display :0.0
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 4096 x 4096
DVI-I-1 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024      60.0*+   75.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
james@gaz:~$ xrandr -display :0.1
Screen 1: minimum 320 x 200, current 1280 x 1024, maximum 4096 x 4096
VGA-1 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024      60.0*+   75.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1

Note that while my two monitors are identical the ports that they are connected to are not. My monitors are, in fact, two of the same Dell model.

sycamorex · 11-15-2011, 03:44 AM

Thanks. Sorry, I forgot about this thread. I'll check it when I go back home.

sycamorex · 11-16-2011, 04:29 PM

Are you using nVidia with TwinView?

Here's what I get:

Code:

xrandr -display :0.0
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 3840 x 1200, current 3840 x 1200, maximum 3840 x 1200
default connected 3840x1200+0+0 0mm x 0mm
   3840x1200      50.0* 
sycamorex@slacks:~$ xrandr -display :0.1
Can't open display :0.1

which is exactly the same as xrandr --current:
xrandr --current

Code:

xrandr: Failed to get size of gamma for output default
Screen 0: minimum 3840 x 1200, current 3840 x 1200, maximum 3840 x 1200
default connected 3840x1200+0+0 0mm x 0mm
   3840x1200      50.0*

jamesf · 11-17-2011, 11:02 AM

I'm running separate X, which means I have a :0.0 and a :0.1. X displays are identified as host:displaynumber.screennumber.

When running separate screens you get :0.0 and :0.1, which I am and you were. When you switched to twinview you got one big, wide X display that is wider than one monitor's resolution, so now you have :0.0

All that is, of course, As I Understand It. ;v)

sycamorex · 11-17-2011, 11:25 AM

That's what I suspected. Last time I tried using separate X ome monitor did not work. I'll have to look into it. Thanks

sycamorex · 07-01-2012, 08:33 AM

Seems like my initial problem was related to the lack of xrandr support in NVidia binary driver. They've recently introduced it.

Code:

xrandr --current
Screen 0: minimum 8 x 8, current 3840 x 1200, maximum 4096 x 4096
DVI-I-0 disconnected (normal left inverted right x axis y axis)
DVI-I-1 disconnected (normal left inverted right x axis y axis)
TV-0 disconnected (normal left inverted right x axis y axis)
DVI-I-2 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 519mm x 324mm
   1920x1200      60.0*+
   1680x1050      60.0  
   1600x1200      60.0  
   1440x900       75.0     59.9  
   1280x1024      75.0  
   1280x960       60.0  
   1280x720       60.0  
   1152x864       60.0  
   1024x768       75.0     70.1     60.0  
   800x600        75.0     72.2     60.3     56.2  
   640x480        75.0     72.8     59.9  
DVI-I-3 connected 1920x1200+1920+0 (normal left inverted right x axis y axis) 518mm x 324mm
   1920x1200      60.0*+
   1680x1050      60.0  
   1600x1200      60.0  
   1280x1024      75.0     60.0  
   1280x960       75.0  
   1024x768       75.0     60.0  
   800x600        75.0     60.3  
   640x480        75.0     59.9