i5-2500k Overclocking issues on Asus P8Z68-V

Hi all, I'm new to overclocking and this is my first try to overclock a CPU.

System specs
Video Card: NVIDIA GeForce GTX560 Ti AMP 1 GB
CPU: Intel Core i5 2500K 3,3 GHz LGA1155
Aftermarket Cooler: Cooler Master Hyper 212+
Power Supply: Corsair TX850W V2 Enthusiast
RAM: Corsair Vengeance 2x4 GB 1600MHz DDR3
Hard drive: Western Digital Caviar Black 750 GB SATA 6 Gb/s
Motherboard: P8Z68-V
Case: Cooler Master 690 II Advanced

Operating system: Windows 7 64 bit
Bios version: 3402 (Newest)

First I followed Theocnoob's guide to the letter. After I got a variety of failures (including BSOD at startup, BSOD before startup, freezing after startup, prime95 BSOD and prime95 fatal rounding error), I tried increasing the voltage all the way to 1.38 with no improvements.

Then I found this guy with very similar build to mine. I mimiced the settings that got his overclock working. No luck. I even increased vcore all the way to 1.4.

Now I'm thinking I might have a hardware problem. It seems that i5 2500k doesn't support my 1600mhz Vengeance RAM. Is this causing my OC to fail?

Here are my BIOS setting. What should I change to make this OC work?






Now lets get this overclock working!

Mmmm...
Your DDR is fine I think.

Disable turbo, set VRM freq to 350.

I had a co worker running those mem sticks and he got alot of bsod's @ stock settings we tried some cheap kingston sticks and no more bsod so he ordred some gskill ripjaw's and had no issues since.

Just a thought.

These setups are pretty easy to oc to 4.5 so you shouldn't be running into any issues yet.

vrm at 350 is a good tip. he could try voltage increase on core to 1.43 ish even but i don't really think its voltage but it could be some chips demand more.

you can run that vcore up to 1.5 if you just want to see if it will post with more vcore if it does then you know what your problem was. if it doesn't then you know it wasn't your cpu voltages but dont leave it like that for 24/7 use if it does post.. keep dialing it down as low as it will go before problems start to happen again the hyper 212 is a decent cooler but cant handle that 24/7.

good luck!

I should also add if you played with the Storage settings this can cause OS boot BSOD's - for instance it was on raid when you installed the OS and you switched it to say AHCI "vice versa" its going to BSOD when its starting windows - or if it was on IDE and you switched it to RAID or ACHI ..you get the picture it will bsod on start up I'm just tossing that out there just in case you made the change unknowingly.

Check out this thread...

i5-2500k Overclocking issues on Asus P8Z68-V/Gen3
http://www.overclockers.com/forums/showthread.php?t=696271

... and this one:

i5 2500k on Asus P8Z68-V LX
http://www.overclockers.com/forums/showthread.php?t=695156

Thanks for the replies.

manu2b said:

...

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SF101 said:

I had a co worker running those mem sticks and he got alot of bsod's @ stock settings we tried some cheap kingston sticks and no more bsod so he ordred some gskill ripjaw's and had no issues since.

Just a thought.

These setups are pretty easy to oc to 4.5 so you shouldn't be running into any issues yet.

vrm at 350 is a good tip. he could try voltage increase on core to 1.43 ish even but i don't really think its voltage but it could be some chips demand more.

you can run that vcore up to 1.5 if you just want to see if it will post with more vcore if it does then you know what your problem was. if it doesn't then you know it wasn't your cpu voltages but dont leave it like that for 24/7 use if it does post.. keep dialing it down as low as it will go before problems start to happen again the hyper 212 is a decent cooler but cant handle that 24/7.

good luck!

I should also add if you played with the Storage settings this can cause OS boot BSOD's - for instance it was on raid when you installed the OS and you switched it to say AHCI "vice versa" its going to BSOD when its starting windows - or if it was on IDE and you switched it to RAID or ACHI ..you get the picture it will bsod on start up I'm just tossing that out there just in case you made the change unknowingly.

Click to expand...

OK. First I tried VRM freq 350 with vcore 1.4: fatal rounding error. Now I'm trying VRM freq 350 with vcore 1.43: blend has been running for half an hour without error. This is actually the first time I don't get an instant error/bsod with 4.5 OC. Highest package temp is 73c.

What next?

P.S. I haven't played with storage settings. I don't even know what they are .

redduc900 said:

Check out this thread...

i5-2500k Overclocking issues on Asus P8Z68-V/Gen3
http://www.overclockers.com/forums/showthread.php?t=696271

... and this one:

i5 2500k on Asus P8Z68-V LX
http://www.overclockers.com/forums/showthread.php?t=695156

Click to expand...

I already referenced the upper link in my OP. Thanks for the second link though.

usually when just a core drops on p95 99% of the time its vcore for me perhaps you just got a not so great ocing chip? i know that these chips range so much can be from simply turning multi up to 45 and done to tweaking for hours to get 4.5, after i found my problem wich was pll OV i could get past 4.4 lol i was stuck there for months. my board is also a turd.

I ran Small FFT and Blend both for an hour now. Both give maximum temp of 77c. What do you guys think about the temps? 1.43 vcore seems sort of high to me. According to this guide, you shouldn't need to exceed 1.4.

Luck of the draw: certainly a stubborn chip. 1.43v and 77°C are perfectly fine though.

I'd say let it prime for a half a day and see if it errors out.. if it doesn't then just leave it how it is and be happy because your at the upper limits of heat on that chip.

The chip wont hit those temps doing regular tasks and as long as its not going much over 80 in prime I think you will be ok.

Some peoples chips vary mine will do 24/7 stable @ 4.7 with 1.43 vcore. 2 other machines i built are like yours 4.5 1.4-1.45 vcore stable.

Some people can do 4.7-4.8 @ 1.38 even its all depending on the chip you get landed with.

I have DRAM Command Mode at cr2. Or 2T. Things get unstable when running cr1.
Also make sure your ram really is 1.5v, if it's 1.65 then that could explain things also.
I have vccio at auto and aida64 says it's at 1.050v. but yours is probably set at 1.1 for stability?

I have cpu configuration all at bios default, or optimized by asus. I do have the multiplier set at 45. This disables the multi setting in AITweaker tab but for some unknown reason I couldn't get my overclock to stick if I left the cpu ratio at auto.
I got a p8p67 board with bios 1503, I never bothered to update my bios because I got my overclock working as it should and reports about newer biosses were not that promising.

Our biosses are quite similar, even the options available, so those should be universal.
I did have problems in the beginning due to my ram settings, for some reason each and every test made my pc crash after a manual overclock. The oc tuner did work and gave me over 4,4Ghz. So after I managed to get my ram stable ( it's 1.65v and I set it at 1.575, runs flawless at that voltage and the rated speed ) I could succesfully overclock upto 4,9Ghz.
After that it became simply to hot and I required too much voltagage. I'm on air cooling and my current speed is fine for me.

Btw, my chip also does 4,8Ghz at 1.385v, but it probably overshoots 1.4v when I game with that speed. When you use an offset voltage then those overshoots happen, with a manual vcore it stays nicely around the value set, on my board. Regardless of stressing with prime or gaming.
At my present settings my highest overshoot is 1.336v when playing a game, while stressing with prime95 shows me 1.280 +- 0.010 because of vdroop. So still all safe for my setup.
That's also why I settle for my current 24/7 overclock, temps stay below 75°C in any scenario (gaming is usually around 60°C).
Would be different with better cooling, maybe someday...

Anyway, goodluck, and make sure your ram is stable, only then can you expect to get a succesfull overclock with sandy bridge.

A breakthrough! I think I pinpointed the cause for my failed OC. After leaving memory frequency to auto instead of setting it to 1600mhz as Theocnoob's guide suggest, I now have a stable overclock at 1.4 vcore. I haven't tried a lower vcore, but I'm sure it will now get closer to 1.35. Will post the results when tested.

Should I now restore to default all the extra settings that were changed? Like VRM freq, VCCIO voltage and CPU current capability, none of which turned out to be the cause?

What should I set my DRAM command mode to?

Bisquit said:

I have DRAM Command Mode at cr2. Or 2T. Things get unstable when running cr1.
Also make sure your ram really is 1.5v, if it's 1.65 then that could explain things also.
I have vccio at auto and aida64 says it's at 1.050v. but yours is probably set at 1.1 for stability?

Anyway, goodluck, and make sure your ram is stable, only then can you expect to get a succesfull overclock with sandy bridge.

Click to expand...

It indeed turned out to be a memory related issue. Thanks for the heads up. I'm certain though, that my RAM is 1.5v. Who is aida64? Yes, my VCCIO was set to 1.1 to try to make the OC stable. Do you think I should switch it back to auto, now that the cause of instability was found to be other than VCCIO?

Thanks all!

I have a stable 4.5 ghz OC now with vcore 1.38. Could someone help me with the questions in the above post?

Kikk said:

I have a stable 4.5 ghz OC now with vcore 1.38. Could someone help me with the questions in the above post?

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Just try experimenting to see if the changes to those settings are necessary. It won't hurt anything to change them back to auto, but it might affect your stability so only change 1 at a time and retest.

^^^^^^^^^+1 always change 1 thing at a time when your at a high end

gregmacknass said:

Just try experimenting to see if the changes to those settings are necessary. It won't hurt anything to change them back to auto, but it might affect your stability so only change 1 at a time and retest.

Click to expand...

^ This

Try to get as base line as possible. If the RAM was the issue all along then you might be able to get that chip on up to 5 or so!