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Core i7 OC ONLY runs under load.

806 Views 12 Replies 6 Participants Last post by  Arkanor
Hi, this is my first post so bear with me.

I have a core i7 920 running @ 3.9 ghz on a gigabyte ud5 mobo. It has bios F6a. I have a sunbeam core contact freezer as a heatsink.

The OC specs are as following

195 bclk
Vcore 1.375v
QPI 1.360v
DRAM 1.64v

QPI multi is 36x
Memory spd multi is 8x
Uncore is 16x
Load Line calibration is enabled

All power saving functions are off, as well as turbo mode. HT is still on.

So the strange thing is, when I run Prime 95 within 5 minutes of startup, on small FFT, I am able to run it for 10 hours or more. But once I turn it off, or never turn it on at all, it just reboots after about 10 minutes. It also crashes when i click the start button on 3d mark vantage.

Is there some sort of power saving feature that is screwing me up? Or is it just bad hardware? I can run at stock just fine.

Thanks for all your help and I apologize if i posted it in the wrong forum.
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Sounds like C1E or w/e intels underclocking setting is named.
I turned off all intel's powersaving options in the bios, so I dont think its that. If anyone has some knowledge about Gigabyte's x58 bios, I turned off everything except for HT and all cores enabled.
Hi JHex2, Try turning off Load Line calibration and HT. Then test your system and see if you can run without any issues. If so, try to up the volts on Vcore a little and turn HT back on. It that works, then come back and try it with Load Line calibration on.
Well wouldnt I want load line calibration on so there's no Vdroop?
definitely fill out your specs...

I'm gonna guess this machine is rock solid at 190 bclk? My gigabyte x58-ds4 needed voltages and timing changes to get above 190... and I run all the powersaving stuff no problem.

my first suggestion would be set the mem multiplier to x6 and test
Thats the weird thing. 3.5 ghz and above I can run prime 95 small fft just fine, but there is no stability otherwise.
Quote:


Originally Posted by JHex2
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Thats the weird thing. 3.5 ghz and above I can run prime 95 small fft just fine, but there is no stability otherwise.

that sounds like a memory issue, have you run memtest with these settings?
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not yet, but what would i do with the results? would it be bad ram? or would i loosen the timings? I tried 6x memory spd and 12x uncore, but i get the same problems with cut offs.
Quote:


Originally Posted by JHex2
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Load Line calibration is enabled

This is your problem, your board is boosting your voltage under load, and letting it fall into instability (what you set it to) when idle. Your actual vCore setting in BIOS is too low.

Load Line Calibration (or any form of circumventing the natural vdroop) is a terrible idea, and it's much better to overcome the issue by adding more vCore, but that's a rant for another thread.
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I ran PC check and memtest, both passed with no errors, so I'm fine with hardware. I tried just tweaking the bclock to 3.0 ghz, with no other changes, and it still crashed on 3d mark vantage, but could still run under load with prime 95 for 10+ hours. Again, it only lasted 10 minutes after turning off prime 95 or never starting it in the first place.
Quote:


Originally Posted by JHex2
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I ran PC check and memtest, both passed with no errors, so I'm fine with hardware. I tried just tweaking the bclock to 3.0 ghz, with no other changes, and it still crashed on 3d mark vantage, but could still run under load with prime 95 for 10+ hours. Again, it only lasted 10 minutes after turning off prime 95 or never starting it in the first place.

Read the above, you need more vCore.
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