I5 2500k Overclocking issues past 4.2Ghz

killer-xz

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Hey guys I've been having a lot of trouble getting my current overclock past 4.2Ghz, and I was wondering if maybe I had a faulty PSU or Motherboard.
Current specs:

CPU = i5 2500k
CPU fan = COOLER MASTER Hyper 212 EVO
Motherboard = MSI Z68A-GD65 (G3) http://www.newegg.ca/Product/Product.aspx?Item=N82E16813130611
PSU = OCZ ZX Series 850W Gold
http://www.newegg.ca/Product/Product.aspx?Item=N82E16817341044&Tpk=ocz%20modular%20850w
GPU: 1 gtx 570


When Overclocking, I have followed the exact same settings as the pictures on this guide: http://forums.overclockers.co.uk/showthread.php?t=18340310

The problem is that whenever I run prime 95, with overclocks over 4.2 Ghz, I end up getting the error of: expected .5 got .4, on my last worker. Does this error mean my cpu is not getting enough voltage?
I also noticed that even when overclocking at 4.5Ghz, my PSU doesn't seem to want to give my CPU more than 1.248v, (this number comes from CPU-Z) whereas other people with my same board, CPU and settings seem to be getting around 1.3v. Is it possible that my PSU is faulty?

In addition when I went into my bios and manually set the CPU core voltage to 1.3, my system failed to boot and I got a blue screen which said: A clock interrupt was not received on a secondary processor within the allocated time interval etc...
Attempts to overclock my video card even at just 840Mhz have also failed. My system ends up crashing after about 1-2 hours of bf3.

My problems are certainly not temperature related as I stay below 70degrees at 100% full load.

I'm really hoping you guys can help me determine if there's an issue with my system, because I paid good money and I was expecting to be able to perform high overclocks.
 
Solution
Well, first off, a direct quote from the link you posted:

Remember your mileage may vary...

Second, Auto voltage for anything over 4.1 or so can be flaky, and the reason it's crashing when you set a manual voltage of 1.300V at 4.5 is that that's not enough Vcore for your particular chip. I'd set a manual voltage of 1.310V or so for 4.5 and test for stability there. If that's not stable, go up 0.005V at a time until it is. Every chip is different, and mine, in particular, needs 1.328V to be stable enough to boot and not BSOD in general in Windows at 4.5 (it's 1.272V at 100% load, though).

Average Vcore for 4.5 on a 2500K is 1.300V-1.330V, just so you you're aware.

I'm not sure what the highest Vdroop setting is for that board...
Well, first off, a direct quote from the link you posted:

Remember your mileage may vary...

Second, Auto voltage for anything over 4.1 or so can be flaky, and the reason it's crashing when you set a manual voltage of 1.300V at 4.5 is that that's not enough Vcore for your particular chip. I'd set a manual voltage of 1.310V or so for 4.5 and test for stability there. If that's not stable, go up 0.005V at a time until it is. Every chip is different, and mine, in particular, needs 1.328V to be stable enough to boot and not BSOD in general in Windows at 4.5 (it's 1.272V at 100% load, though).

Average Vcore for 4.5 on a 2500K is 1.300V-1.330V, just so you you're aware.

I'm not sure what the highest Vdroop setting is for that board, but that's what you want to use to keep the voltage steady under load.

Also, nothing is wrong with your PSU. That has nothing at all to do with this.

 
Solution

killer-xz

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Hey DJDeCiBeL, thanx a lot for the quick reply!

I followed your advice and you were right, setting the vcore at 1.3 was not enough! In fact, for an OC of 4.4Ghz, at a core voltage of 1.36v I can now boot into windows and run Prime95, but after 30min I will BSOD. I'm guessing I should continue pushing the Vcore untill stable, but not go over 1.4v.

I am also getting large voltage drops on the core voltage when under load. From about 1.32v at idle to 1.256v under load. I'm guessing this is because of the Vdroop controls which I have no idea how to use. My guess is increase it as much as possible?

On my version of my BIOS, the only option for Vdroop I have is "Vdroop Offset Control" and I have the option to set it on: Auto; +12.5%; +25%; +37.5%; +50% etc until +100%. Do you have an idea of what I need to set this at? (it is currently on auto)
 
Are you sure about that Vcore? 3.6V should be frying your CPU (like it may die within hours, if not minutes). The Vcore for a 2500K should never go above 1.52V (1.45V for long term use). 1.380V should be the absolute max that you would need for 4.5 (I can get to 4.7 on 1.380V).

I'm hoping that you mean 1.360V, 1.320V and 1.256V, which would still be a bit high for 4.4, but MUCH more in line with what it should be.

But 100% is what the Vdroop should be set to.
 

killer-xz

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OH wow yes, 1.36 is what I meant, very sorry! 1.3 ; 1.4; 1.256 etc. I will edit my other comment. I won't have time to test the Vdroop offset at 100% today, but as soon as I test it tomorrow, I'll post my results. Thanks again for the help!
 

killer-xz

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Hey DJDeCiBeL.

I changed the Vdroop offset to +100% and it doesn't seem to have helped. Even though my Core Voltage is set to 1.35v in the bios, when running Prime95, CPU-Z says that the Core Voltage is at 1.24v. Is there something wrong? When idle, my Core Voltage is still around 1.3v.
 
Well, 100% should, in theory be maximum, but try 12.5%, and if that doesn't help, try all of them, lol.

If none of them do anything, then I'm not really sure, although the fact that it has "Offset" in the name may mean that it's only active when using Offsets for Vcore (which I prefer anyway).

That seems strange, but if it doesn't have any effect when using a manual voltage, that's the only thing that makes much sense.
 

rdm3

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I've been running a i5-2500K@4.4Ghz at 1.29V and it's stable (for a few weeks). HOWEVER, if i try to overclock the video card at all i run into problems.

-Will increasing my vcore (now at 1.29V) help to stabilize the system when OCing my 7870, or am I missing something?
-My temps are good (even after 4hrs of PRIME95), but even when I upped the voltage to 1.35V my PC would shut down (enter power save mode) after only a few mins of WoW
-I feel like I should be able to overclock my video card and maintain my cpu overclock, but no luck so far........any suggestions?
 


That shouldn't have anything to do with the CPU, but you should really start a new thread so more people see this.

It sounds like a GPU/Driver/PSU problem to me, though (could be either of the three or even a combination).
 

killer-xz

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Hey DJDeCiBeL.

I tried changing the value of the Vdroop Offset control, but had no luck. In the bios, my core voltage is set to 1.365v and Vdroop to 100%. However, My Core Voltage in CPU-Z keeps on dropping from 1.33 to exactly 1.256 when I run Prime 95 blend tests. Also, after about 30min of prime 95, I will BSOD.
If I lower the Vdroop percentage, ex to 12.5% or 50%, my system will freeze the second I start Prime95 and will BSOD. So i'm guessing that when the offset is at 100%, I'm having the least voltage drop.

I'm unsure what to do now.. Like I said before, attemps to overclock my GPU have also failed. Is it possible that I have a hardware problem? Thankfully everything is still under warranty.
 


I don't think so, but I suppose anything's possible.

I'll be honest though, I'm not really a fan of MSI boards. From what I've seen they just don't OC very well (at least all but the absolute top end MSI boards) and their quality is questionable.

Asus and Gigabyte are where it's at for good OC's.
 


You're welcome, and I hope that helps. I'm just worried that the high Vdroop, even at max LLC, is a symptom of bad design (bad VRM implementation) more than it is a symptom of something physically wrong with the board. We'll see though.