Overclocking a Q6600@3.6GHz with P5N72-T Prem'

rob_cunningham

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I have an Asus P5N72-T Premium mobo and I was wondering if anyone can help me out with my voltage settings to get 3.6ghz stable using a Q6600?

my setup is:

P5N72-T Prem'
Q6600 (G0) VID 1.250v
Asus Silent Knight II CPU cooler
2x2gb OCZ Reaper 1066 at 5-5-5-15-2T (2.1v)

I've tried two different sets of voltages and both seem to work ok until i try running Prime95 (using large ffts)

First set of voltages:

CPU 1.475v
PLL 1.50v
VTT 1.46v
Mem 2.1v
NB 1.42v
SB 1.55v
1.2HT 1.20v
GTL Auto
Loadline Calibration disabled
High I know but these were the lowest i could get but prime was still unstable. Idle temps are mid to high 40's.

I read a couple of threads and tried these:

CPU 1.4125v
PLL Auto
VTT 1.34v
Mem 2.1v
NB Auto
SB Auto
1.2HT Auto
GTL +50mv
Loadline enabled

These are lower but still unstable in Prime still. Temps run high 30's to low 40's idle.

Also, this is strange. although these two sets of voltages seem pretty stable if i shutdown for the night and reboot in the morning the system crashes just after log in. Seems i get better luck just after i have been using my machine on lower settings and warmed things up? I'm probably wrong but it is strange.

Can you help shed any light on the solution to my problem. I'm finding it very difficult to find anything on these mobos.

Thanks in advance,

Rob.
 

doomturkey

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Try taking your Q6600 up to the max recommended voltage, 1.5V. If it doesn't work then just settle for 3.2ghz or so. Its plenty fast anyways, I can run my Q6600 @ 3.6 stable but 3.2 just gives it extra stability, and besides, thats the highest stock intel CPUs run at.
 

Zecow

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which core failed? Some boards allow you to tweek voltage on core 1&2/ 3&4. I'd increase it to 1.45 - I'm on 3.6 as well @ 1.45
 

rob_cunningham

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Hi thanks for the prompt replies.

I don't think my problem is a question of voltage on the CPU. I can run on much higher Voltages - I've tried 1.5125v in the bios and this doesn't help stability, just runs hotter.

When I run Prime normally it just Crashes (either BSOD, sys reboots or screen hangs and doesn't recover).

Do you or does anybody know if/how changing the the other voltages in my bios can improve my stability? I know VTT helps massively and i've read posts that say increasing the VTT and using a GTL_Ref of +50mv "reduces noise" but also read that people should be careful when adjusting the GTL_REF.
 

rob_cunningham

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I think I may have found some stable ground using the following settings:

CPU: 1.4375v
PLL: Auto
VTT: 1.46v
Mem: 2.1v
NB 1.52v
SB: 1.55v
1.2 HT: 1.25v

GTL_REF: +50mv
Loadline: enabled
Seems to be ok under normal running for last few hours. Also ran 3dmark06 which gave me an 850 point increase over stock. Core temps idle at 42-47C yet to test under load. CPU-Z reads vcore at 1.376v.

I will test in Prime in the morning. I will try to get voltages down if possible but i'll see how she goes from here first.
 

teamlosigp

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@doom turkey ya dink the max recommended voltage by intel to the Q6600 is 1.35vlts at 1.5 that is not long term voltage, know something before u post, JESUS!!!!
 

Priv

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Ehm, the max recommended voltage on the Q6600 is 1.5v, sorry to burst your bubble. You are probably thinking about the 45nm's, the max recommended voltage on those is 1.36v.
 

rob_cunningham

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i've dropped down to 1.36875v on the Cpu now and CPU-Z gives a vcore of 1.296v

I haven't tried Prime yet but general running is pretty good.