I have a problem with sleep and my two graphic cards. By now, I have disabled the jMicron (eSata), Samsung (sata6) and ASMedia (usb3) controllers. With Lion my system was not able to go to sleep, the screen just kept getting black, but the pc was still running. With Mountain Lion, it is able to sleep and wake, but with two graphics card, wake takes about 5 min. With a single GTX560 it sleeps and wakes with no problems.
A year ago I had a P8Z68-V PRO (non gen3), with the same configuration (old bios, not 3xxx version), Lion (10.7.1) was able to sleep and wake properly (had to change because the onboard audio was not able to switch correctly from front panel to rear panel).
I have been working for about a month for the Mountain Lion upgrade, and it is almost finished. I still have to test the disabled controllers (and find the right kexts....), but everything else is working perfectly (apart sleep ).
I attached my DSDT and system.log.
Thanks for your time
PS I'm using iMac12,2 in smbios.plist
Edit: Added my EFI strings.