Computer freezes

Elimination

I am at a loss as to what is causing this. I recently upgraded my Mobo and CPU to an Asrock Extreme 4 z77 and an intel 3770k i7, put on a coolermaster n520. This is not my first time by far building a PC or upgrading, this is pretty routine for me and nothing went wrong with the installs.

My problem is I get random freezes at times, there is no errors, no bsods, no error logs other than a log of the unexpected shut down. It seems to happen completely randomly, it isnt constant and only happens once every few days at most. I dont have to be doing anything specific, i can be listening to music, browsing the net, and it will just lock up forcing me to hard reset. Even in gaming I can game for hours with no issues. I AM overclocked moderately with the 3770k but only to 4.2ghz. I ran Prime95 and temps never went bout 75 after an hour. And no freezes. Ran MEMtest while i slept/went to work, came back roughly 14 hours later to zero errors, so it isnt that either....

I am at a loss as to what is causing this, its a recent re-install of windows as well, as i had to do that because of the upgrade of Mobo and CPU. It doesn't APPEAR to be a lemon CPU or mobo, as my tests havent caused any of the freezing.

Anyone else have any advice??

Great Scott

First, the obvious - have you tried running at base clocks for a few days to see if that's the source?

Other than that, since you aren't getting any sort of BSOD, my thought is some type of obscure memory error or a power supply problem. If you keep your PC running 24x7 it's also possible that a memory leak in your browser can cause freezes.

Independantly of CPU/memory clockrates, see if loosening your memory timings and/or running at one speed grade lower solve the problem. I've found that memory speed is essentially irrelevant for overall performance of the later Core-series Intel computers.

Elimination

I really don't think its a memory problem, I have the timings locked in pretty good (not on auto.) I am running my PC with no OC right now. But the fact that it ran on Prime 95 and doesnt freeze during gaming indicates its likely not a CPU problem. I also ran SFC /scannow last night,and chkdsk to see if that helps. Also yes, memory speed is almost irrelevent for later series intel CPU's as their memory controllers only do 1333 or 1600 so any higher is almost pointless.

I dont run 24/7 either. My PSU is basically brand new (Antec Gamer high-current 950 Watt bronze.) and it doesn't freeze during high power draw times normally. It freezes mostly during random web browsing or when the PC is idle. It's only ever frozen once during a game. One think I've noticed is after running every fix I know of last night my overall PC performance has improved, I also re-installed all my drivers. We'll see if I get anymore freezes, if I don't i'll put my OC back on...and see if i get freezes again that way i'll know for sure.

Elimination

Well I fixed it. I reset my OC settings and re-did them all, and i even managed to get an even higher OC (4.5 ghz.) stable, and the freezing is gone. No idea what it is I changed that was different from before but there we have it.