# Two monitors plugged into graphics card; how to tell X which one to use.



## caesius (Nov 10, 2010)

I have a dual screen set up that works fine. However there is a game that doesn't work well with two screens so I want disable the dual set up to play it. Easy enough, I just comment out parts of the xorg.conf file and restart X. 

My problem is this: when I revert to a single monitor set up, the *wrong* monitor is used as the display (i.e., my smaller monitor I have to the side). How do I tell X that I want to use the other monitor?

FreeBSD 8-STABLE,  x11/nvidia-driver

Cheers.


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## wblock@ (Nov 10, 2010)

It should not be necessary to change xorg.conf or restart X.  xrandr(1) should let you do that all by itself.  Don't know if nVidia drivers support xrandr, though.


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## caesius (Nov 10, 2010)

wblock said:
			
		

> It should not be necessary to change xorg.conf or restart X.  xrandr(1) should let you do that all by itself.  Don't know if nVidia drivers support xrandr, though.



Yeah you're right nvidia drivers don't support it.


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## phoenix (Nov 11, 2010)

Are you sure about that?  xrandr works here for multi-monitor setup via nvidia binary drivers.

```
Section "Screen"
        Identifier      "Screen0"
        Monitor         "Monitor0"
        Device          "Device0"
        DefaultDepth    24
        Option          "TwinView"              "True"
        Option          "MetaModes"             "nvidia-auto-select, nvidia-auto-select"
        SubSection      "Display"
                Depth   24
        EndSubSection
EndSection
```


```
[fcash@fcash-desktop  ~/Downloads]$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 2560 x 1024, current 2560 x 1024, maximum 2560 x 1024
default connected 2560x1024+0+0 0mm x 0mm
   2560x1024      50.0*
```
*krandrtray* GUI allows me to selectively disable displays via the Multiple Monitor tab.

(Granted, this is on a Kubuntu station, as my FreeBSD systems have Intel graphics.  But, I'd be surprised if this didn't work on FreeBSD.)


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## DutchDaemon (Nov 11, 2010)

Or simply use x11/nvidia-settings.


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## caesius (Nov 11, 2010)

phoenix said:
			
		

> Are you sure about that?  xrandr works here for multi-monitor setup via nvidia binary drivers.
> 
> ```
> Section "Screen"
> ...



Apologies, you are correct. What I meant to say was nVidia *Twinview* doesn't work with xrandr. I'm using Twinview. Although I'll look into what you have said.

Just for clarity: if I want to use my main monitor as the primary display, at the moment I'm having to unplug the small one so that only the main monitor is connected, then restart FreeBSD.

Cheers

EDIT: I didn't read that carefully enough; you *are* using Twinview. Hmmm I'll check that out.


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## SirDice (Nov 11, 2010)

If it's something that uses SDL you can set *SDL_VIDEO_FULLSCREEN_HEAD*.


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