Overclocked i5 2500k and battlefield 3 problem

Hi all.

Im having a little problem with my overclocked i5 2500k.

I have it overclocked to 4.5ghz with voltage set to auto on the mobo and bclk set to 100mhz. (mobo is gigabyte ga-z68xp-ud4)

Now I have used intel burn test and ran 20 test @ high and the temps are 55-60c and it is stable, i have also ran prime 95 for hours and hours and all is stable.

The problem comes when playing battlefield 3, if i leave the cpu at stock settings there is no problem but when it is overclocked for some annoying reason the computer will freeze completely and i have to do a hard reset and then I get an error when it boots back up and the code I get is Bbcode 124.

I am lost for any ideas as to the problem due to IBT and prime running fine and stable but BF3 just does not like overclock and it is not stable with that game, but please remember when cpu is at stock settings bf3 never crashes for me.

Any ideas?

Your error code is hardware related. You say it only occurs when you OC so I would tend to think you have an incorrect bios setting that is causing the hard lock.

Please list your complete hardware specs such as ram and graphics card.

Your temps look fine but I do not like auto voltage settings when OCing. Run HWMonitor when you run Prime95 and tell us when your max voltage is to the cpu.

What's your QPI/Dram voltage set too. It could be cpu voltage, but at the frequency, it could easily be QPI voltage that needs to be raised. Also since you're prime stable, and freeze in game, I think that points to the memory controller/ram.

Im not sure now how to proceed. Any guidance would be appricated.

I have read many stickies on this forum and other places on the net but not sure how to go about getting a safe overclock on my system as the last thing i want to do i blow up my mobo and cpu.

The board is a gigabyte ga-z68-ud4 rev 1.0
memory is corsair vengance 4 2gb sticks (8gb total) and i will post in a few hours the exact spec of the memory

I want the overclock at 4.5ghz

I have set the bckl at 100mhz and turned off spead spectrum at it was showing in cpuz as 99.8mhz bckl but still fluctuates between 99.8mhz - 100mhz

I set the voltage to auto

changed the cpu multiplier to x45

left everything else untouched (auto or default settings)

Changing the multiplier is only the first step in getting a stable OC rig. You generally have to manually set other options in the bios to get 24/7 stability.

I am not familiar with your bios/mobo but I found a post that shows you other options you need to set for your specific motherboard.

http://www.overclock.net/t/1044981 [...] 8-ud4-mobo

I would try a qpi voltage of around 1.30 and raise/lower until stable. That is obviously after you run prime95 small fft for a couple hours.