Right, so currently I've OC'd my 2500k as a test, stock voltage was 1.1v, upped to 4.5ghz @ 1.25V and now I've tried further pushing my 2500k to 4.8Ghz on air @ 1.36V, bear in mind the highest the core temp has gone is 75'c on the hottest core, seems pretty stable soo far as I've prime 95'd it, another thing to add is that it's paired with a gtx660 and the performance gains for myself have been around 20-40% On specific games, Gta4, Tomb Raider, etc. is it worth keeping it for that valuable performance gain? and the gain has been in the minimum FPS as I use vysnc.
Unlucky mate, I had huge problems getting past / trying to get it stable @4.7, Had to bump it up from around 1.3 to 1.36, I think my limit is around 4.8-5. I've seen people get stupid Oc's at low voltages on 2600k's and 2700k's.