SLI and Ubuntu 8.04, trouble on multiple screens geforce 8600GT

[zackboll]

Hello,

I ended up getting a pair of 8600GT as I wanted to experiment with the CUDA compiler a little bit. I am having trouble getting SLI to work.

my current /etc/X11/xorg.conf looks like

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 1.0  (buildmeister@builder26)  Thu Feb 14 18:13:41 PST 2008

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 1.0  (buildd@yellow)  Tue Mar  4 20:28:57 UTC 2008

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 1280 0
    Screen      1  "Screen1" LeftOf "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Files"
    RgbPath         "/usr/X11R6/lib/X11/rgb"
EndSection

Section "Module"
    Load           "dbe"
    Load           "extmod"
    Load           "type1"
    Load           "freetype"
    Load           "glx"
EndSection

Section "ServerFlags"

# Removed Option "Xinerama" "0"
    Option         "Xinerama" "1"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"

    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "XXX M24EI4"
    HorizSync       30.0 - 83.0
    VertRefresh     56.0 - 71.0
    Option         "DPMS"
EndSection

Section "Monitor"

    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor1"
    VendorName     "Unknown"
    ModelName      "WDE LCM-19v5"
    HorizSync       30.0 - 82.0
    VertRefresh     56.0 - 76.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Videocard0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 8600 GT"
    BusID          "PCI:1:0:0"
    Screen          0
EndSection

Section "Device"
    Identifier     "Videocard1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 8600 GT"
    BusID          "PCI:1:0:0"
    Screen          1
EndSection

Section "Screen"

# Removed Option "metamodes" "DFP-0: 1920x1200 +0+0; DFP-0: 800x600 +0+0; DFP-0: 640x480 +0+0"
    Identifier     "Screen0"
    Device         "Videocard0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "TwinViewXineramaInfoOrder" "DFP-0"
    Option         "metamodes" "DFP-0: 1920x1200_60 +0+0; DFP-0: 800x600 +0+0; DFP-0: 640x480 +0+0"
    Option         "SLI" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"

# Removed Option "metamodes" "DFP-1: nvidia-auto-select +0+0"
# Removed Option "metamodes" "DFP-1: 1280x1024 +0+0; DFP-1: nvidia-auto-select +0+0"
# Removed Option "metamodes" "DFP-1: nvidia-auto-select +0+0"
    Identifier     "Screen1"
    Device         "Videocard1"
    Monitor        "Monitor1"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "metamodes" "DFP-1: 1280x1024_60 +0+0"
    Option         "SLI" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection

This is the one that works fine, as you can see from the config file, I have two displays, a 1280x1024 and a 1920x1200.

when I run the command

"nvidia-xconfig --sli=on"

I get this xorg.conf file

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 1.0  (buildmeister@builder26)  Thu Feb 14 18:13:41 PST 2008

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 1.0  (buildd@yellow)  Tue Mar  4 20:28:57 UTC 2008

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 1280 0
    Screen      1  "Screen1" LeftOf "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Files"
    RgbPath         "/usr/X11R6/lib/X11/rgb"
EndSection

Section "Module"
    Load           "dbe"
    Load           "extmod"
    Load           "type1"
    Load           "freetype"
    Load           "glx"
EndSection

Section "ServerFlags"

# Removed Option "Xinerama" "0"
    Option         "Xinerama" "1"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"

    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "XXX M24EI4"
    HorizSync       30.0 - 83.0
    VertRefresh     56.0 - 71.0
    Option         "DPMS"
EndSection

Section "Monitor"

    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor1"
    VendorName     "Unknown"
    ModelName      "WDE LCM-19v5"
    HorizSync       30.0 - 82.0
    VertRefresh     56.0 - 76.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Videocard0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 8600 GT"
    BusID          "PCI:1:0:0"
    Screen          0
EndSection

Section "Device"
    Identifier     "Videocard1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 8600 GT"
    BusID          "PCI:1:0:0"
    Screen          1
EndSection

Section "Screen"

# Removed Option "metamodes" "DFP-0: 1920x1200 +0+0; DFP-0: 800x600 +0+0; DFP-0: 640x480 +0+0"
    Identifier     "Screen0"
    Device         "Videocard0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "TwinViewXineramaInfoOrder" "DFP-0"
    Option         "metamodes" "DFP-0: 1920x1200_60 +0+0; DFP-0: 800x600 +0+0; DFP-0: 640x480 +0+0"
    Option         "SLI" "on"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"

# Removed Option "metamodes" "DFP-1: nvidia-auto-select +0+0"
# Removed Option "metamodes" "DFP-1: 1280x1024 +0+0; DFP-1: nvidia-auto-select +0+0"
# Removed Option "metamodes" "DFP-1: nvidia-auto-select +0+0"
    Identifier     "Screen1"
    Device         "Videocard1"
    Monitor        "Monitor1"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "metamodes" "DFP-1: 1280x1024_60 +0+0"
    Option         "SLI" "on"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

But then my second display, the 1280x1024 does not receive input. When I got to nvidia-settings, I see it disabled. I re-enable it in the GUI, save my xorg.conf, and restart X11 server, and then it still shows up as disabled.

Does SLI not work on multiple screens in Linux? I am really at a lost what to do here, any help/input would be appreciated.

Thanks,
Zack

[zackboll]

bump

[jrharvey]

when you go to the nvidia-settings, do you use sudo? To actually save the file you must be root.

[jrharvey]

BTW what do you think is better, 2 8600gt's or 1 8800gt?

[zackboll]

when you go to the nvidia-settings, do you use sudo? To actually save the file you must be root.

Yeah, I run nvidia-settings as root. I mainly got two 8600 GT because I am running 3 monitors and plan to add a fourth. In terms of stream processors, I think the 8800GT would be better, I believe it has 112. Each 8600GT has only 32 processors.

I don't believe nvidia driver support is very good for linux in 8XXX series and they do not support hardware accelerated video decoding like the 6XXX and 7XXX series. They do have a specialized compiler using CUDA though which is why I went with the 8XXX series.

Zack