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I want to work in dual screen mode with the monitors not mirroring, but extending each other and I want the total resolution to be 3360x1050. When I try to apply dual screen (that is uncheck "Same image in all monitors" option) it says "required virtual size 3360x1050 does not fit available size 1680x1680".

Additionally, When I try to detect my monitors both are pink monitors, that is the monitors seem to not be detected as separate monitors

So the question seems to be two-fold: How do I detect the monitors as separate monitors? and How do I increase the available size?

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Video card? Driver? Logs? – Ignacio Vazquez-Abrams Sep 8 '11 at 7:19
up vote 0 down vote accepted

Some dual head setups require declaring the maximum display size in the Xorg configuration file, /etc/X11/xorg.conf. Create this file by running Xorg -configure as root (or Xorg :1 -configure if you already have a GUI running). Copy the generated configuration to /etc/X11/xorg.conf, then make the desired modifications.

In the Screen section, you need to declare a display with a total size of at least 3360 by 1050. The Screen section might look like this:

Section "Screen"
        Identifier      "Configured Screen"
        Device          "Configured Device"
        DefaultDepth    24
        SubSection "Display"
                Depth           8
                Virtual         3360 1050
        SubSection "Display"
                Depth           24
                Virtual         3360 1050
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thx, it solved it perfectly. – Rythmic Sep 9 '11 at 8:27

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