yea as far as i know there is a setting, the name of which I can't remember at the moment, but without it the 2600 doesn't recover from sleep properly (it resumes a standard multiplier or lower). Fortunately, the computer is my dads photo editing computer, not a main computer or my computer (I would have switched out for another mobo because I use sleep ALL THE TIME). But yea, without the setting sleep won't work at over a multiplier of 40 on the 2600k is the short explanation. Sin said he personally had a BIOS that had the fix, but since it isn't a "major" issue as its a sandy not an ivy, they gigabyte isn't as worried about fixing it as quickly as some other issues. I understand this, seeing as ivy is what this was "built for". but still, I was one of the first 2600k users on here with a UD5H, would be nice to get the sleep ability sooner or later. lol. But I am glad it works for your 2500k, because like you said, sleep issues are super annoying.