I'm trying a manual setup of Xorg 1.9.5, for two identical monitors connected to the VGA and DVI ports of an nVidia GeForce 6600. I get the X Server to run using a single screen, and it appears identical on both monitors. Started with Xorg -configure, and have tried to use two screens with the same device, but only one is recognized. It automatically recognized the "modesetting" driver, through the nouveau module in the kernel.

I had this working OK with Xorg 1.7.7 and similar hardware, using the nv driver and the "DualHead" and "DynamicTwinView" Device options. I don't find these options documented for nouveau and wonder if it is still possible to use it, as it loads by default into the kernel on my newer system (Slackware 13.37.0).

If the kernel driver needs to be removed, I have the nv and nouveau X drivers available. Any recomendations on which to use for DualHead would be appreciated.

  • nouveau can do dual head. I used it once a long time ago. However I abandoned it due to its instability and went with the proprietary driver, and thus I dont remember how to get it working. Just saying it is possible. – phemmer Mar 21 '12 at 1:35
  • @Patrick Thanks, that was encouragement enough to keep me going. – dmaestro12 Mar 21 '12 at 17:31

Yes, the nouveau driver works, but it has to be explicitly selected in the Device section. When I saw the conflict between the nouveau kernel module and the nv driver (older nVidia driver, probably going away), I left the default driver "modesetting" as configured by Xorg -configure - never thinking the nouveau X driver would/could be used - until I read the following:

ATM , the nvidia driver and the nv driver both don't like KMS on...

But nouveau was built for KMS* to be on...

From http://forums.debian.net/viewtopic.php?f=10&t=52787
*KMS = "Kernel Mode Switching"

Yes, of course it makes sense (now ;-) that the kernel 'nouveau' module does something different than the X server 'nouveau' driver, and both are required!

For my dual-head setup, I set Screen 0 / Screen 1 in otherwise identical (other than Identifier) Device sections. This is needed to specify different monitor connections on the single video card I am using.

I also have Option "Xinerama" "True" in the ServerFlags section - I think that is needed for my window manager to avoid placing windows straddling the monitors.

So, a minimum working configuration I require is this:

Section "ServerLayout"
    Identifier      "X.org Configured"
    Screen          "Screen0"  0 0
    Screen          "Screen1"  RightOf "Screen0"

Section "ServerFlags"
    Option  "Xinerama" "True"

Section "Screen"
    Identifier      "Screen0"
    Device          "nVidiaNV43_0"

Section "Screen"
    Identifier      "Screen1"
    Device          "nVidiaNV43_1"

Section "Device"
    Identifier  "nVidiaNV43_0"
    Driver      "nouveau"
    BusID       "PCI:4:0:0"
    Screen      0

Section "Device"
    Identifier  "nVidiaNV43_1"
    Driver      "nouveau"
    BusID       "PCI:4:0:0"
    Screen      1
  • Nouveau also works well with Xrandr, Option "Xinerama" "True" is not the only choise. – Stéphane Gimenez Mar 22 '12 at 16:37
  • Am I finding that they are mutually exclusive? Xorg.0.log shows RandR enabled, but when I execute xrandr, it reports the extension is missing. – dmaestro12 Mar 22 '12 at 20:21
  • Yes they are mutually exclusive. – Stéphane Gimenez Mar 22 '12 at 20:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.