Thanks this helped a lot for me moving to Mountain Lion. I built a silent computer based on the taiwanese NoFan computer case (their signature feature being the huge circular cooling element occupying most of the case internals). Fanless power supply as well. SSD drives so no moving parts.
For some time I settled for the motherboard Intel graphics and never got dual display going. But now I read about NVidia native support in Mountain Lion so it looked tempting to try to end up with a working multi display setup. I decided on a passively cooled "ZOTAC GeForce GT 640 2GB PhysX CUDA PCI-Express 3.0, "ZONE Edition", DDR3, 2xDVI, mini-HDMI" and just hoped things would turn out. With only millimetre margins the Zotac card fit into oneof the very few card slots no covered by the huge CPU cooler and it takes up two card slots in width for all the passive cooling. With the target boot drive prepped using Unibeast 1.6 to load my appstore purchased Mountain Lion I booted up with the card in place and two monitors. I also used MultiBeast to get the configuration right (no DSDT, no GraphicsEnabler). A few forum posts got me on the track of what kexts to configure for my board. Once I figured things out I got a clean boot. I am amazed. Only remaining issue is resuming with working video following standby. I might figure that out too with time. I will try hooking up a monitor to the mini HDMI slot of that card and see if I get a third monitor up as well.
