Okay, Hello! I bought this i7-4790k off Ebay a while ago. (Yes I know, used components are scary.) However, it works alright -- except, if it goes into turbo, or anything over 4Ghz exactly, my entire computer will lock up after a bit and I have no choice but to hard-power it down. And this even happens sometimes (rarely) when it isn't going past 4Ghz. I was trying to play RE3 Remake and it freezes up my PC after about 20 minutes, the temperatures aren't anything absurd so I know it's not overheating. They're around ~50c - ~60c while playing a game and idle around ~32c-38c. I have no idea what this problem is, but I bought the processor with the intention of OCing it, and I can't do that at all. So I'm stuck with this stock i7-4790k that hates working sometimes. Anyone have any suggestions what could be wrong? I haven't messed around with voltage or anything like that yet. It's all stock and default. My mobo is the MSI Z87-GD65. Hopefully someone can help, if not I'm just gonna have to move over to a new AMD CPU when I get some money, since this processor has been giving me a headache. Also, I have the Hyper 212 EVO for my cooler, and I have a 700w PSU so I doubt it's that either. I never had any of these problems until I upgraded from my i5-4690 to the i7-4790k. I did fully reinstall windows after installing the new CPU as well, and yes, BIOS are up-to-date. Hopefully someone can help, thanks guys. Maybe it's just a faulty CPU. -- Oh also, it's paired with a XFX Radeon 5700 XT, in case that's relevant.