Originally Posted by magnite
You don't need to disable the power saving features, disabling it can help but it's not always needed and varies from board to board. Remember though, if you want the cpu to drop to a lower voltage at idle, you will need to use offset voltage as opposed to manual.
I did exactly that, but had stability problems. Wanted to do 24/7...
I had set my i7-3930k to offset +.0005 (couldn't do 0 ) for target of 45 ratio on turbo and EIST enabled. The voltage would tune according to some magic preset and go up to 1.37 under load. I wasn't comfortable with going higher. Some people OC to 48 ratio+ on that voltage. So with that setting I'd get a freeze or BSOD with "clock interrupt not received on secondary processor" maybe once a day. This would happen usually when I went afk in a game, so I figure that it didn't have enough juice when it switched clock. I've read on this forum that the BSOD actually it translates into "give more juice to CPU".
So I set it manually to 1.35 2 days ago. and I haven't had it fail on me (need more time to confirm).
So to sum it up - from my own experience, i'd say to always keep set voltage rather than offset but try to keep EIST on if you want to save power.