Proposed GA-X79-UD3 + i7-3930K Build for Data Transfer and Video Transcoding

[kundica]

It is not full power management but you might want to look at http://code.google.com/p/xnu-sleep-enabler/

Some x79 users have had success with sleep enabler. I haven't tested it on my setup yet since I don't really need it. Maybe tonight.