Dual screen on kubuntu with intel graphic card

I've tried to run dual screen on my laptop Dell Laitude D620, but I've never had enough time to sort it out. There are two ways how to configure dual screens on Xserver, dynamically with xrandr and statically with xorg.conf. I've always have problems with editing xonrg.conf, so I prefere xrandr.




The output of command xrandr (without parameters) looks like this:

Screen 0: minimum 320 x 200, current 3360 x 1050, maximum 3360 x 1050
VGA connected 1680x1050+1680+0 (normal left inverted right x axis y axis) 434mm x 270mm
   1680x1050      60.0*+
   1280x1024      75.0     59.9
   1152x864       74.8
   1024x768       75.1     60.0
   800x600        75.0     60.3
   640x480        75.0     60.0
   720x400        70.1
LVDS connected (normal left inverted right x axis y axis)
   1280x800       59.9 +   60.0     59.9
   1280x768       60.0
   1024x768       60.0
   800x600        60.3
   640x480        59.9
TMDS-1 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 434mm x 270mm
   1680x1050      59.9*+
   1280x1024      75.0     59.9
   1152x864       74.8
   1024x768       75.1     60.0
   800x600        75.0     60.3
   640x480        75.0     60.0
   720x400        70.1
TV disconnected (normal left inverted right x axis y axis)

Lines marked with stars (*), are currently in use.

Port names for Intel driver:

VGA - Analog VGA output


LVDS - Laptop panel


TV - Integrated TV output


TMDS-1 - First DVI SDVO output


TMDS-2 - Second DVI SDVO output

Intell chipset 965 has limitation for maximal virtual desktop size 2048x2048, if the sum of width of both of your desktops is greater you have to disable dri
in xorg.conf. It is some graphic acceleraion

Section "Module"
        Disable         "dri"
EndSection

then you have to extend your virtual desktop (also in xorg.conf)

Section "Screen"
        Identifier      "Default Screen"
        Monitor         "Configured Monitor"
        Device          "Configured Video Device"
        SubSection "Display"
                Depth 24
                Virtual 3360 1050
        EndSubSection
EndSection

In my case it is 3360x1050px (two 22").


You can change position of screen by command:

xrandr --output VGA --left-of TMDS-1 --auto

I've encountered strange error:

xrandr: cannot find crtc for output VGA

I've solved it by turning the laptop screen off

xrandr --output LVDS --off

Then everything worked as I imagined. With xrandr you don't have to restart xserver after each change, so it is pretty much pracitcal.

Useful links:
http://www.intellinuxgraphics.org/dualhead.html
http://www.thinkwiki.org/wiki/Xorg_RandR_1.2