I have an I5 4690. It came stock of course at 3.5. I first took it to 4.0, pretty basic and everything ran stable no problems. I decided to try to run it at 4.5 ( I read where guys were doing it) Everything I have runs great, no issues at all, EXCEPT Prime 95. When I run the torture test after about 20 - 25 mins it gets the temp up to 78-79, and I had heard dont let them get hotter then middle 70s at long periods of time. Do you guys think this I5 can handle to I just not run the Prime??? Someone told me one time, " if you cant run prime / torture test for 12 hours it's not a stable system. I have had no shut downs, blue screen's Etc. Etc. What do you think????