Dual Monitor, TWO vid cards spanning desktop

[jengle]

just thought i'd add to the collective knowledge base. i'm an absolute newbie but recently got my monitors spanning nicely. i've got a samsung syncmaster 170mp and a generic cmc 17 ad running on an nvidia and an ati, respectively. i've seen several posts that come close to doing the trick but not one that used this setup exactly.

Section "Device"
Identifier "ATI Technologies, Inc. Rage 128 PF/PRO (AGP TMDS)"
Driver "ati"
BusID "PCI:1:0:0"
EndSection

Section "Device"
Identifier "nVidia Corporation NV11 [GE FORCE 2 MX/MX 400]"
Driver "nvidia"
BusID "PCI:2:0:0"
EndSection

Section "Monitor"
Identifier "CMC 17 AD"
Option "DPMS"
EndSection

Section "Monitor"
Identifier "Samsung SyncMaster 170mp"
Option "DPMS"
HorizSync 50-80
VertRefresh 70-76
EndSection

Section "Screen"
Identifier "screen0"
Device "ATI Technologies, Inc. Rage 128 PF/PRO (AGP TMDS)"
Monitor "CMC 17 AD"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
EndSection

Section "Screen"
Identifier "screen1"
Device "nVidia Corporation NV11 [GE FORCE 2 MX/MX 400]"
Monitor "Samsung SyncMaster 170mp"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
EndSection

Section "ServerLayout"
Identifier "Default Layout"
Screen "screen0" 0 0
Screen "screen1" LeftOf "screen0"
Option "Xinerama" "on"
Option "Clone" "off"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
EndSection