I5 760 overclocking stuck at 3.93

dalmvern

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Hey guys, I recently built a new machine and have been trying to push it to 4.0 GHz but I am getting hung up at 3.93 GHz.

Here are my computer specs:
Intel i5 760 Lynnfield
Asus P7P55D-E Pro
Cooler Master Hyper N 520
G.Skill Ripjaws 1600 2x4GB
MSI TwinFrozr II HD6950
Corsair Enthusiast Series TX650 PSU

And here is a screencap running P95.

P95test061611.jpg


This is the further I can currently get it and keep it stable. If anyone has any recommendations for me I would greatly appreciate them. I am fairly new at overclocking so if further information is needed on whats going on under the hood, I can get that for you.
 
Solution
In my opinion 1.32v on IMC is pretty high (1.4v is Intels stated max. if I am not mistaken). I would suggest starting from scratch. Higher IMC/VTT voltage only really improves stability when your base clock is high. I prefer to keep mine below 1.3, 1.25 preferably (I like to play it safe).

When i overclock I usually set the clock i would like and then pump quite a bit of voltage into the vcore. Once I have tested and found the lowest possible vcore voltage I start upping the VTT voltage and then lower the vcore again until I have found the sweet spot. However, I have not yet taken my i5 to 4.0GHz but that was the approach I took when overclocking my i3.

Another thing to bear in mind is that you should underclock your ram when...

cromedome

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A 1.1GHz overclock is relatively high considering you have a quad core. However, I would think, even with an average chip, you should be able to hit 4.0GHz. Perhaps you have a bad chip? Your CPU vcore is pretty high for 3.9GHz, have you tried lowering that and changing the VTT voltage at all? Tell us what settings you have changed in your BIOS and we will help some more. :hello:
 
How have you been overclocking?

Like cromedome said, VTT should be raised in conjunction with Vcore. I definitely wouldn't bother going more than 1.35V, as 1.4V is Intel's stated max. Raise up the VTT to compensate.

Also, underclock your RAM so you can rule out the possibility of it causing issues. Then once you get an OC you like, put the RAM back up to speed.
 

dalmvern

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What I have been doing is stepping up the BCLK by one and raising both the VCore and the VTT by one step as well and testing it, if P95 fails (I usually run through 6 tests as a prelim) then I step up the VCore once, if that fails I take the VCore back down, up the VTT and test again. If that fails, I bring the VCore back up to match the VTT and test again.

I know you cant tell from my SS but I believe the VCore is set to 1.33 and the VTT is set to 1.3275.

I will post what I have changed in the BIOS this evening.
 

dalmvern

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Alright so BIOS settings, here it goes:

Intel SpeedStep Off
QPI Auto
CPU Voltage Manual
IMC Voltage Manual
DRAM Voltage 1.5000
CPU PLL Auto
PCH Voltage Auto
Load-Line Calibration Enabled
CPU Spread Spectrum Disabled
PCIE Spread Spectrum Disabled
 

cromedome

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In my opinion 1.32v on IMC is pretty high (1.4v is Intels stated max. if I am not mistaken). I would suggest starting from scratch. Higher IMC/VTT voltage only really improves stability when your base clock is high. I prefer to keep mine below 1.3, 1.25 preferably (I like to play it safe).

When i overclock I usually set the clock i would like and then pump quite a bit of voltage into the vcore. Once I have tested and found the lowest possible vcore voltage I start upping the VTT voltage and then lower the vcore again until I have found the sweet spot. However, I have not yet taken my i5 to 4.0GHz but that was the approach I took when overclocking my i3.

Another thing to bear in mind is that you should underclock your ram when overclocking the cpu. Once the cpu is stable and you are happy, you can then get your ram up to speed.
 
Solution

dalmvern

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Thanks for the advice chromedome, I tried a different approach and started out at 1.4v and underclocked my memory as you said and got it stable at 4.01 now im in the long process of bringing the voltages down to find the sweet spot. Ill post another SS when I get it where I like it.
 

dalmvern

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Alright, after doing a bit of tinkering, I think these are the voltages I am going to be running with, they appear stable but I have not run extended tests on them to make sure, but at 4.01 GHz my Vcore is at 1.3625 and the VTT is at 1.3.

Again, thanks for all the advice guys. :sol:



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