Xorg : how many monitors ?

[Luigi Falco]

Hi to all,
I'm using xorg for drive 8 monitors connected to 4 ASUS nvidia 7600 GT
dual dvi.

I don't want to use twin options but I would to have 8 separates
screens. I followed this configuration :

    Section "Device"
        Identifier  "nvidia0:0"
        Driver      "nvidia"
        # Edit the BusID with the location of your graphics card
        BusID       "PCI:2:0:0"
        Screen      0
    EndSection

    Section "Device"
        Identifier  "nvidia0:1"
        Driver      "nvidia"
        # Edit the BusID with the location of your graphics card
        BusId       "PCI:2:0:0"
        Screen      1
    EndSection

    Section "Device"
        Identifier  "nvidia1:0"
        Driver      "nvidia"
        # Edit the BusID with the location of your graphics card
        BusID       "PCI:2:0:0"
        Screen      0
    EndSection

    Section "Device"
        Identifier  "nvidia1:1"
        Driver      "nvidia"
        # Edit the BusID with the location of your graphics card
        BusId       "PCI:2:0:0"
        Screen      1
    EndSection


    Section "Screen"
        Identifier  "Screen0"
        Device      "nvidia0:0"
        Monitor     "Monitor0"
        DefaultDepth 24
        Subsection "Display"
            Depth       24
            Modes       "1600x1200" "1024x768" "800x600" "640x480" 
        EndSubsection
    EndSection

    Section "Screen"
        Identifier  "Screen1"
        Device      "nvidia0:1"
        Monitor     "Monitor1"
        DefaultDepth 24
        Subsection "Display"
            Depth       24
            Modes       "1600x1200" "1024x768" "800x600" "640x480" 
        EndSubsection
    EndSection


    Section "Screen"
        Identifier  "Screen2"
        Device      "nvidia1:0"
        Monitor     "Monitor2"
        DefaultDepth 24
        Subsection "Display"
            Depth       24
            Modes       "1600x1200" "1024x768" "800x600" "640x480" 
        EndSubsection
    EndSection

    Section "Screen"
        Identifier  "Screen3"
        Device      "nvidia1:1"
        Monitor     "Monitor3"
        DefaultDepth 24
        Subsection "Display"
            Depth       24
            Modes       "1600x1200" "1024x768" "800x600" "640x480" 
        EndSubsection
    EndSection

For semplicity I post only an a example configuration. Tomorrow I can post exactly the xorg.conf.

With this configuration I have this problem. 

If I create a serverlayout with all 8 monitor it run correctly only in 4 monitor (each video card drive 1 monitor). 
I I try to run a servicelayout with only 2 cards I view 4 monitor and then each video card drive 2 monitors correctly.

I ask you : is there a limit to a number of screens in xorg ? If no, do you have an answer to this problem ?

Luigi

-- 
Luigi Falco
Centro Reti e Sicurezza
Centro per la Sismologia e l'Ingegneria Sismica
Istituto Nazionale di Geofisica e Vulcanologia
mail : falco at gm.ingv.it
tel. : 0825/421919 0825/421917
Fax  : 0825/421937