More than 2 monitors

Hi All,

Long time lurker, 1st time poster. I really need to get a 3rd monitor working on my hackintosh system.

I have just upgraded to mountain lion on my ga-z68xp-ud3r based system. It has been working really well with 2 monitors for some time. Initially with a Powercolor 6850 and now with a Gigabyte 640gt . I moved to the 640gt as it has native driver support in mountain lion, and I was hoping to be able to use both video cards at the same time. I wasn't able to get this to work. (triple monitors with the 6850 card would crash after a few minutes. triple monitors with the gt640 card just doesn't seem to work - 3rd monitor will operate during post, but switch off when the two other screens come on).

If I add another gt640 card to the system (giving me 2x gt640 cards), will it work automatically due to the driver support?

Note - there is a quirk with the ga-z68xp-ud3r mboard that requires PCIRootUID=1 in the boot options. No matter what other settings I change, I seem to need to leave this setting in place to successfully boot.

Thanks for your help.

Did you get an answer? I I have the same card and wanted to add two additional monitors... Thanks

If your third monitor is 1920x1200 or less you could use the on-board graphics along with your gt640 by injecting the video string into your plist. see
http://www.tonymacx86.com/mountain-lion-desktop-support/61216-10-8-how-enable-hd4000.html