It didn't work for me. Now I have to reinstall everything.
One thing Windows has OS X beat is with being able to restart in safe mode and going back to the previous save point and restarting again as if nothing ever was touched on the HD.
Boot into safe mode (-x) or single user mode (-s) and verbose (-v) to find out where the system is hanging. Boot using the Boot-132 method to add the options at boot time ala Windows XP. If you need details, google os x boot options. One thing windows doesn't have is native support to create an image of a drive to an external USB drive for backup in case the upgrade doesn't goes South.
If you follow aquamacs tutorial for EFI Strings, you can run two cards, you need to read each one separately. I have been running 2 280GTX's for a long time this way.
Has anyone gotten the EVGA GTX 295 Coop working? I don't care about SLI; I just want the single GPU working in the retail install.
UPDATE: I took the easy way out. Returned the coop, which the store actually encourage if it doesn't work for you, and exchanged it for GTX 285 2 GB. BTW, a pair GTX 260 in SLI has better performance but not twice the performance.
Are all of these commands safe? I currently have Windows 7 and Ubuntu on here, I don't feel like reinstalling what took days to set up. It would be better if the tutorial explained what everything does.