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I5 2500K 4.7 GHz stable in Prime95 but fails during boot up

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March 16, 2012 10:40:52 PM

Hi,

I've been running my i5 2500K stable at 4.5 GHz 1.35V for quite a while now, so I decided to overclock it a little further, but I've some problems. I now try 4.7 GHz. First tried 1.39V, BSOD after a few minutes. 1.40V seems stable, same for 1.41V. I ran 6 hours of Prime95 4.7 GHz 1.41V for 6 hours with no errors. But unfortunately sometimes during bootup, around 1 out of 5 boots, it doesn't wanna boot up, then I reboot, and ones it succeeds to reboot, it says "Overclocking Failed!" and bla bla bla. Which I don't understand because it's 6 hours stable in Prime95. So I tried 1.42V and even then I got these error message after some boots. So I just don't understand. It seems my CPU is quite a bit voltage hungry. Right under here are my pc specs and OC settings.

Asus P8Z68-V Pro, i5 2500K, Mushkin 4GB 1600 CL6, EVGA GTX 580 Superclocked, Crucial m4 128GB SSD, OCZ 700W.

OC settings:

OC mode: X.M.P.
BCLK: 100.0
Multiplier: 47
Internal PLL voltage: Enabled
Memory frequency: DDR3 1600
EPU power saving: disabled
CPU current capability: 130%
Load-line: extreme
Duty: extreme
Phase: extreme
VRM: Auto
Voltage mode: manual
VCore: 1.42V
VDRAM: 1.65V
VCCIO: 1.1V
CPU PLL: 1.9V
Spread Spectrum: disabled
Intel Adaptive Thermal Monitor: Enabled
EIST: disabled
Execute disable bit: Enabled
CPUID: disabled
Intel Virtualization: disabled
C1, C3, C6: disabled


I have no idea what to change. Any suggestions? Perhaps it's normal that my CPU doesn't wanna make it past 4.5-4.6 GHz?

Thanks in advance!

Arjen


a b à CPUs
a b K Overclocking
March 16, 2012 10:54:05 PM

Just do 4.4GHz BECAUSE after 4.4GHz, games wont show much improvement probably between from 4.5 to 5GHz is 1FPS... Your Vcore is pretty HIGH for a 4.7GHz OC... Best if you just get 4.5GHz OC instead of higher because there's no point...
March 16, 2012 10:55:01 PM

I have been running into similar problems with a Asus P8Z68-V LE, with an i5-2500k @ 5.0Ghz.

Out of nowhere, the computer wouldn't boot past hanging at the bios screen. I had to remove the battery to reset the bios, and the computer booted up fine. When I re-upped the multiplier, the computer would work, but after 5 boots over a couple of days, the same problem - a hang at bios screen occurred. I took out the battery, and then only returned the multiplier to 45 (4.5 Ghz). It's been fine since, except that my USB 3.0 ports and external harddrive isn't reading. I'm not sure if the USB controller has problems, and if these two things are related.

It makes sense that the hardware isn't up to the overclock and wears down from it's prime over time. I'm just not sure that's what is occurring.

I do note that you have Intel Virtualization disabled. I would turn that on and install and use LucidLogix. It shouldn't affect your overclock and should also improve video resources. It means my onboard video card gets caught for Windows ExperienceIndex score rather than my dedicated card. But I can live with it I guess.
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March 16, 2012 10:55:42 PM

As usual I"m getting answers to questions I didn't ask. And yes I do notice a differencei n games, around 3-5 fps from 4.5 GHz to 4.7 GHz.

Do you have any suggestions for my problem?
March 16, 2012 11:11:26 PM

I believe there may be something with the 1155 platform. When I first read your thread title I automaticaly figured you were running a gigabyte motherboard, as I have a p67 ud7 where at 4.8ghz it boots almost every time while other times it loops. I've heard of this on asrock motherboards as well.

Could be a dmi thing being maybe the tech is not refined enough to handle cpu speeds so high. It used to bother me at first but I've gotten over it. Mine usually loops about 2-3 times before succesfully booting with my intended overclock. If I try to intervene and reboot it on my own my giga board will also tell me my solid oc has failed.

Is your board actually looping or attempting a post and then goes black and stops?
March 17, 2012 6:20:29 AM

In my original post I didn't say I did have a Gigabyte board. I have the Asus P8Z68-V Pro. My problem is that when it boots up, it sometimes shuts off again after ten seconds. This is a problem that every Asus board has, it just reboots and succesfully boots the second time when I'm running 4.5 GHz 1.35V. However, when I run 4.7 GHz, and I need at least 1.4V, then it boots succesfully most of the time. However sometimes it boots and the screen stays black, then shuts of after 10 seconds, restarts, but doesn't boot succesfully, and the screen just stays black, nothing happens. After I waited 30 seconds I decided to shut it off. Then I restart it again, and once it boots succesfully, and at the screen with the "American Megatrends" logo, it's saying something like: "Overclock failed! Please press F1 and run setup." However, when I press F1 nothing happens.

I don't understand this, because I ran 6 hours stable in Prime95 with no errors. When I increase the voltage I have the same problem. If you look at my settings, are there any settings that I might change?
a c 185 à CPUs
a c 150 K Overclocking
March 17, 2012 6:54:16 AM

Kind of like me:

Overclock passes 10 hour OCCT run
Fails 30 second P95 run.
March 17, 2012 8:37:19 AM

arjenboerdijk said:
In my original post I didn't say I did have a Gigabyte board. I have the Asus P8Z68-V Pro.


I didn't say you had a gigabyte board. I said I had a gigabyte board and the issue may be across the platform as a whole. You must have misread something I said.

Though by the sounds of it your issue is slightly different and am unfamiliar with it. Could very well be related.

I can say this though. When sandy bridge came out I had been running what I believed was the latest version of prime95 and passing tests successfully and then blue screening while gaming, errors trying to post etc. Came to find out I had to get a tailored version of prime that stressed the new elements of the modern architecture sandy bridge had to offer. I'm not saying this is what's happening in your case, though it could be.
March 17, 2012 8:45:13 AM

Well, I just downloaded Prime95 a few days ago, the x64 version. And I don't have any problems at all in games, no BSOD's or crashes. I only sometimes have the problem that my pc doesn't wanna post at startup.
a c 145 à CPUs
a b K Overclocking
March 17, 2012 9:26:17 AM

RAM and overclocking:
You also need to make sure you don't overclock your RAM.

Some motherboard BIOS' can automatically keep your RAM at the proper frequency, such as 1600MHz. Depending on how you play with your multipliers however it's easy to overclock the RAM by the same as the CPU.

Anyway:
1) make sure the RAM stays at the proper frequency
2) run MEMTEST to be sure your RAM is stable
3) Drop your CPU frequency to at least 300MHz below where you notice instability/crashing

*Basically your pushing your system to the limit. I personally think you should keep it at the stable frequency and stop trying to figure out how to get that last 200MHz out of your CPU. Besides, when your CPU becomes unstable like that the chance of destroying it goes up significantly despite the protection circuitry.
March 17, 2012 9:28:29 AM

My RAM is not overclocked. It's rated at 1600 MHz 6-8-6-24. One question, can faster RAM limit overclock capabilities?

My RAM is surely stable.

My overclock is working perfectly at 4.5 GHz and below.
a c 145 à CPUs
a b K Overclocking
March 17, 2012 9:38:34 AM

arjenboerdijk said:
My RAM is not overclocked. It's rated at 1600 MHz 6-8-6-24. One question, can faster RAM limit overclock capabilities?

My RAM is surely stable.

My overclock is working perfectly at 4.5 GHz and below.


NO.
RAM is pretty independent from the CPU in that sense. There's a common clock they share. The only way the CPU can be affected by RAM is if the RAM is so slow that the CPU is waiting for it. I suppose if you were working on VIDEO that was sitting in your RAM and you had a 4.5GHz CPU and only 1000MHz RAM there might be an issue but I don't know those specifics.

I experimented with overclocking my i7-860 but it made little difference to the FIVE games I benchmarked. Crysis, for example benchmarked EXACTLY the same at 3.5GHz as it did with 2.8GHz (HD5870 graphics card).

The BETTER the card, the more likely overclocking a CPU will make a difference. I'm going to retest a few games once I get my GTX680 (such as Crysis 2 with HD Textures).
March 17, 2012 9:54:47 AM

Ok, I have changes some things and it seems the problem is now barely there.

I changed LLC from Extreme to Ultra High. Changed VRM frequency from 350 to 370. In the Advanced tab under JMB I changed Show OROM messages to Disabled. Under Boot tab I changed OPROM messages from Force Bios to Keep Current.

Then I updated my BIOS from version 1101 to 3203.

Then I did lots of full shut down reboots. After having done 15 boots succesfully I thought the problem was solved and was really happy. Until boot 16, my pc didn't post, screen stayed black, shut of, and rebooted automatically. However, this time, instead of the screen staying black again, it booted, BUT - it hanged upon starting Windows. So did a few more boots, and upon boot 19, the same thing happened, it didn't post, restarted, and hanged upon Windows starting (the logo froze). If this happens 1 out of 15 boots then I can live with it. However it's annoying, cuz I don't understand why it happens. I do not have any BSOD's, crashes or any other instability in OS, it's just this boot problem that sometimes occurs.
a b à CPUs
a b K Overclocking
March 17, 2012 1:31:06 PM

arjenboerdijk said:
My RAM is not overclocked. It's rated at 1600 MHz 6-8-6-24. One question, can faster RAM limit overclock capabilities?

My RAM is surely stable.

My overclock is working perfectly at 4.5 GHz and below.



Not all CPU, motherboard and chipsets are created equal. Sometimes you got lucky, sometimes you're not. My question is: what CPU cooler are you using? While running Prime95 what is the highest temperatures you got? At idle what temps you got?
March 17, 2012 1:35:07 PM

My cooler is the Scythe Mugen 2 REV B. Quite a cheap cooler (40 euros) BUT - it only runs around 5C hotter than the Corsair H100. I have the Antec 902 case, and it's a very well ventilated case. My idle temps are around 28-32, temps under full load are around 55-65 depending on the room tempature.

But the strange thing is, that it's perfectly stable in OS, games and Prime95, but it sometimes fails to boot, and I get an error message, I only get this when I overclock 4.7GHz+. 4.6 seems fine also. It's just strange, because I also tried 1.42V, and don't want to increase it much further. Sometimes it also hangs on Windows bootup, the logo just freezes up. You can find my OC settings in my original post. Perhaps it's just normal that my i5 2500K doesn't wanna make it past 4.5-4.6GHz, no matter how much voltage I apply?
a b à CPUs
a b K Overclocking
March 17, 2012 4:37:12 PM

arjenboerdijk said:
My cooler is the Scythe Mugen 2 REV B. Quite a cheap cooler (40 euros) BUT - it only runs around 5C hotter than the Corsair H100. I have the Antec 902 case, and it's a very well ventilated case. My idle temps are around 28-32, temps under full load are around 55-65 depending on the room tempature.

But the strange thing is, that it's perfectly stable in OS, games and Prime95, but it sometimes fails to boot, and I get an error message, I only get this when I overclock 4.7GHz+. 4.6 seems fine also. It's just strange, because I also tried 1.42V, and don't want to increase it much further. Sometimes it also hangs on Windows bootup, the logo just freezes up. You can find my OC settings in my original post. Perhaps it's just normal that my i5 2500K doesn't wanna make it past 4.5-4.6GHz, no matter how much voltage I apply?



Don't over voltage you might damage the CPU, 4.5 GHZ and 4.7 GHZ is no much difference in performance. Okay the temps are good. Are you using an SSD? If so, then it might need some firmware updates.
a c 227 à CPUs
a c 105 K Overclocking
March 17, 2012 5:41:57 PM

You are aware that 1.4v and up can kill a Sandy Bridge chip in a matter of weeks due to electromigration right? For long term stability you really want to be closer to 1.3v.

Also I am guessing that with cas 6 RAM it's not 1.5v? Going over 1.5v can cause stability issues and voids the CPU warranty. Just the low cas can cause issues with Sandy Bridge systems. The integrated memory controller can have a hard time dealing with low timings.
March 17, 2012 5:45:39 PM

anort3 said:
You are aware that 1.4v and up can kill a Sandy Bridge chip in a matter of weeks due to electromigration right? For long term stability you really want to be closer to 1.3v.



I don't wanna be naive but I think that's bullshit because Intel states 1.52 is maximum safe voltage. And I know people running those voltages for months without problems at all.
a c 227 à CPUs
a c 105 K Overclocking
March 17, 2012 6:06:43 PM

arjenboerdijk said:
I don't wanna be naive but I think that's bullshit because Intel states 1.52 is maximum safe voltage. And I know people running those voltages for months without problems at all.



The testers here at Tom's have had it happen in enough chips to warn people in their review articles.

An interesting read.

http://www.tomshardware.com/reviews/automatic-overclock...
a c 145 à CPUs
a b K Overclocking
March 19, 2012 12:15:47 AM

ALL CPU's have the potential to fail, and the chance of failure increases significantly as it is overclocked (not just the voltage).

I'll say this again, and take it as you want:

*Run your CPU at a MINIMUM of 300MHz lower than the point at which it crashes.

(besides, is it really worth all these headaches to squeeze out that last few percentage points of potential processing power which MAY or MAY NOT make any real world difference depending on the application or game you are using?)
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