I have two NVidia 8400GS 250MB cards. I used OSx86 Instruments to create a plist for one graphics card and copied it a second time for my different graphics card.
With GFXUtil and the primary card installed I appeared up the DevicePath wich is PciRoot(0x0)/Pci(0x1,0x0)/Pci(0x0,0x0). Then I took out the primary card and insert the second card within the second slot and dit the same thing, PciRoot(0x0)/Pci(0x6,0x0)/Pci(0x0,0x0).
I've copied the above values into the plist created with OSx86 Tools. Then I created a hex file out of the plist with GFXUtil and put the output into com.apple.boot.plist.
After putting both card in the machine and boot up Mac OS X I get a kernel panic. When utilizing the verbose possibility I get a black screen. Please advise.
I managed to get it working with the plist below.
<plist version="1.0">
<dict>
<key>PciRoot(0x0)/Pci(0x1,0x0)/Pci(0x0,0x0)</key>
<dict>
<key>@0,compatible</key>
<string>NVDA,NVMac</string>
<key>@0,device_type</key>
<string>display</string>
<key>@0,name</key>
<string>NVDA,Display-A</string>
<key>@1,compatible</key>
<string>NVDA,NVMac</string>
<key>@1,device_type</key>
<string>display</string>
<key>@1,name</key>
<string>NVDA,Display-B</string>
<key>NVCAP</key>
<data>
BAAAAAAAAwAMAAAAAAAABwAAAAA=
</data>
<key>NVPM</key>
<data>
AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA==
</data>
<key>VRAM,totalsize</key>
<string>0x10000000</string>
<key>device_type</key>
<string>NVDA,Parent</string>
<key>model</key>
<string>nVidia GeForce 8400 GS</string>
<key>name</key>
<string>display</string>
<key>rom-revision</key>
<string>nVidia GeForce 8400 GS OpenGL Engine [EFI]</string>
</dict>
<key>PciRoot(0x0)/Pci(0x6,0x0)/Pci(0x0,0x0)</key>
<dict>
<key>@0,compatible</key>
<string>NVDA,NVMac</string>
<key>@0,device_type</key>
<string>display</string>
<key>@0,name</key>
<string>NVDA,Display-A</string>
<key>@1,compatible</key>
<string>NVDA,NVMac</string>
<key>@1,device_type</key>
<string>display</string>
<key>@1,name</key>
<string>NVDA,Display-B</string>
<key>NVCAP</key>
<data>
BAAAAAAAAwAMAAAAAAAABwAAAAA=
</data>
<key>NVPM</key>
<data>
AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA==
</data>
<key>VRAM,totalsize</key>
<string>0x10000000</string>
<key>device_type</key>
<string>NVDA,Child</string>
<key>model</key>
<string>nVidia GeForce 8400 GS</string>
<key>name</key>
<string>display</string>
<key>rom-revision</key>
<string>nVidia GeForce 8400 GS OpenGL Engine [EFI]</string>
</dict>
</dict>
</plist>