Enable SLI in Linux: My Xorg.conf as an example

The SLI mode was a little harder to enable. Here is how i got it working

Install the driver according to the nvidia howto.

sax2 -r -m 0=nvidia doesent work with SLI setup

use

sax2 -r -c0 -m0=nvidia

instead. assuming that your disply is hooked up to card 0. Else you can use Card 1 but card 1 will not work for SLI

Now here was that catch: when I wanted to enable SLI GPU 0 as detectd by

nvidia-settings

needs to be the same as chip0 as reported by

sax2 -p

the can be identified by ther pci adress. And the display has to be hooked up to card 0 too. else the display will be scrambled when you starup the display.

I had to change the Init Disply first to PEG(slot2) to get this accomplished.

then you type

nvidiea-xconfig --sli=on

and your set. It si imortant that the frst available Xscreen is the screen with you monitor hooked up to it if have more that one configured in you xorg.config.

Heres the sections relevant to xscreen config of xorg.conf as a reference with sli enabeled:

Section "Module"
Load         "dbe"
Load         "type1"
Load         "freetype"
Load         "extmod"
Load         "glx"
Load         "v4l"
EndSection


Section "Monitor"
Option       "CalcAlgorithm" "XServerPool"
DisplaySize  338 270
HorizSync    30-82
Identifier   "Monitor[0]"
ModelName    "ACER AL1714"
Option       "DPMS"
VendorName   "ACR"
VertRefresh  43-75
UseModes     "Modes[0]"
EndSection

Section "Device"
BoardName    "GeForce 6800 GS"
BusID        "4:0:0"
Driver       "nvidia"
Identifier   "Device[0]"
VendorName   "NVIDIA"
EndSection


Section "Screen"
DefaultDepth 24
SubSection "Display"
  Depth      15
  Modes      "1280x1024" "1152x864" "1024x768" "800x600"
EndSubSection
SubSection "Display"
  Depth      16
  Modes      "1280x1024" "1152x864" "1024x768" "800x600"
EndSubSection
SubSection "Display"
  Depth      24
  Modes      "1280x1024" "1152x864" "1024x768" "800x600"
EndSubSection
SubSection "Display"
  Depth      8
  Modes      "1280x1024" "1152x864" "1024x768" "800x600"
EndSubSection
Device       "Device[0]"
Identifier   "Screen[0]"
Monitor      "Monitor[0]"
Option         "SLI" "on"
EndSection


Section "ServerLayout"
Identifier   "Layout[all]"
InputDevice  "Keyboard[0]" "CoreKeyboard"
InputDevice  "Mouse[1]" "CorePointer"
Screen       "Screen[0]"
EndSection


Section "DRI"
  Group      "video"
  Mode       0660
EndSection

Nvidie Linux Driver README