How does something like this happen?

asoccerplayer99

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Jul 21, 2006
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I have an E8400 C2D running at 3.6 GHz, on a Gigabyte GA-EP35-DS3L motherboard. Its been running at 400MHz FSB with a 9x multiplier for weeks, fully stable. I have proper cooling.

Yesterday I moved my PC from one side of my desk to the other, and had to unplug the power cord to re-organize it all. When I turned my system back on, I got a BSOD.

I determined that it is the processor, but wtf, what happened? I can run the board at >400MHz FSB with a lower multiplier, and it runs at <400MHz FSB with the 9x multiplier, but the processor refuses to go over 3.6 GHz. What would cause the processor to do something like that, when it was easily reaching 3.6GHz before I unplugged my power cord?

Any help would be greatly appreciated :)

And before anyone asks, yes:
I powered down the system first
I tried increasing the voltages
I used proper OC'ing techniques
There have been no hardware changes
My memory runs fine at higher FSB frequencies, and always has a direct ratio (2, 2.4, etc)

The rest of my specs are:
2x2GB OCZ DDR2-800 5-5-5-18
AC Freezer 7 Pro cooler
Vista Ultimate x64
eVGA 9800GTX
 

stoner133

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I'm confused, it ran at 3.6 on one side of the desk. You moved it to the other side and it blue screened. Then you say you determined it was the cpu but it runs at 3.6, and it refuses to go above 3.6 while it easily reached 3.6 before you unplugged it. Looks like 3.6 on either side of the desk so whats the problem other then the one blue screen?
 
CPUs and OC'ing is fickle anyhow. Could be as little as the CPU moving a micron or two when you moved the computer case.

I've got a new cooler being shipped to me, and I'm already wondering whether my OC will become unstable after pulling the existing heatsink off and putting on the new one when it gets here. ;)
 


Hehe I didn't catch that error. I'm guessing the OP means it won't OC to 3.6Ghz anymore. Considering he said he plugged it back in and it immediately went BSOD. At least I'm hoping it was a typo. Would be silly to be upset that it won't OC further...
 

asoccerplayer99

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Yea, sorry, let me clarify. It was at 3.6 before, but when I unplugged to move it, then started the system again, it wouldnt load Windows at 3.6 anymore, I have to back down the CPU speed to get it to load into Windows properly. Basically I didnt change anything at all except I unplugged it and plugged it back in to get the BSOD. I know its the processor because I can back off the multiplier and raise the FSB above 400MHz without a problem (I brought it in 5MHz increments up to 415 to test, including testing at 400), just the processor will not go above 3.6GHz.

I dont think the heatsink came loose, I have the processor right now clocked to 3.2GHz (8x 400Mhz) using the same voltages as I had been when I had it at 3.6, and the temps are fine. I even lapped the processor and cooler a month or so ago before I started overclocking it any to make sure the temperatures were OK, and before my BSOD troubles my temps were outstanding.

Should I maybe try reseating the whole deal or something?
 

Technophobe

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You said you tried increasing the voltages but I would still wager that its your CPU voltage that needs tweaking. There have been lots of cases where a CPU can run perfect with a certain voltage and after a while of usage it needs a bit more to make it stable again. People refer to this as 'burn in'.
 

asoccerplayer99

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I guess this is where my noobishness comes in as an overclocker. What are normal voltages for a 3.6ghz E8400? I remember seeing anywhere between 1.2 and 1.4, and I have my board set to 1.325V. In the BIOS it says the normal voltage is 1.225V. The oddest thing about it though is that I have the exact same motherboard and processor right here at work, and when I run Prime95, it shows in CPUZ as only drawing 1.104 at 3.6GHz. I'm so confused...

Maybe I'll just swap out the processors :p
 

I

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May 23, 2004
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Can't you just move it from the evil side of the desk back to the good side?

I suspect that when you unplugged AC, some bios setting was lost because the bios has a bug. Review all settings, and even if they all look ok, save the settings when you exit the bios menus just for the heck of it.