I overclocked my i5 3570K to 4.2Ghz on 1.12 vcore. It can do 20 passes in LinX with all memory selected with good temps. I can play all my games without any crashes or restarts. I decided to try an overnight Prime95 blend test, newest version with AVX, and it crashes after about 7 hours in. Tested the RAM few weeks ago and all the sticks checked out fine. Should I be worried? I have no problems with the computer otherwise. Not sure if I should consider my system "unstable" because of this, even though it handles everything that I throw at it game and program wise without any issues.