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F8-x86_64 on the Acer Ferrari 3400LMi
the fly by the command line tool xrandr, and there is no need to restart the X
server.
10.2.1 Virtual screen size
RandR works its magic by means of a virtual screen that is larger than the a
single monitor.
The size of the virtual screen is reported as the maximum value by the command:
# xrandr -q
Screen 0: minimum 320 x 200, current 1400 x 1050, maximum 1400 x 1200
...
In this case the size is 1400x1200, which is the default virtual screen size for this
setup. The default screen size is too small for serious dual-head configurations.
This value needs to be increased by setting the Virtual option in the Display sub-
section in /etc/X11/xorg.conf:
SubSection "Display"
Viewport 0 0
Depth 24
Virtual 3000 2000
EndSubSection
This is the most (only) important setting needed in xorg.conf. However, in order
to enjoy hardware support for 3D acceleration the virtual screen may not be
larger than 3000x2000. This limitation differs for the various driver, but for the
radeon driver the limitation is 3000x2000. This is sufficient for having an
external monitor running at 1600x1200 side-by-side with your internal display as
1400x1050.
After modifying xorg.conf you need to restart your X server, ie. logout and logon
again. Now, check your settings once again:
# xrandr -q
Screen 0: minimum 320 x 200, current 1400 x 1050, maximum 3000 x 2000
VGA-0 connected (normal left inverted right x axis y axis)
1280x1024 59.9
1152x864 75.0 74.8
1024x768 84.9 75.1 70.1 60.0 43.5
832x624 74.6
800x600 84.9 72.2 75.0 60.3 56.2
640x480 84.6 75.0 72.8 66.7 60.0
720x400 87.8 70.1
LVDS connected 1400x1050+0+0 (normal left inverted right x axis y axis)
0mm x 0mm
1400x1050 60.0*+
1360x768 59.8 60.0
1280x800 60.0
1152x864 60.0
1280x768 60.0
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