I overclocked my new 2500k to 4.5Ghz, and ran Prime95 without problems for about an hour (temps maxed at 63 celsious). BF3 and Saints Row 3 run fine.
However, PCSX2 and Civ 5 lockup the whole computer within 5 minutes of launching when OCed. They don't crash at stock speeds.
I've tried CPU voltages between 1.325-1.335. Most recently, 1.335 didn't work. Civ 5 crashed when the game started. However, P95 had no problems running for a hour......temps are 35ish at idle and 65ish at load.
Am I missing something? Should I raise voltages more? Or do I just have a bad chip?
The missing elements may shed some light on this picture, like fully listing your specs make and model#s, so we can see if there's a possible problem that doesn't have a thing to do with the actual overclock.
Like an underpowered system trying to push dual GPUs, or mismatched memory or wrong timings and such as that for example.
What you have enabled or disabled to reach this 4.5ghz overclock?
It's always a good idea to list your full specs first, then address the problem?
What test or tests you are actually running in Prime95?