P5Q DLX & Q9450 Overclock advice

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My new build (see sig) has been running for a week perfectly fine, so it's time to start overclocking. Trouble is, I'm new to Intel / DDR2 overclocking, so some guidance would be much appreciated.

For info - my RAM is Corsair 4GB DDR2 XMS2 PC2-6400C5 TwinX (2x2GB).

What I've done so far is set FSB to 333MHz, RAM to 333MHz - this took the ratio from 5:6 (on auto) to 1:1 - a good thing I think? This kept the CPU at stock 2.66GHz.

I set the RAM manually to what CPU-Z says is SPD - 5-5-5-18 @ 1.8V

The VID of the Q9450 is 1.235V, I have this on auto at present. I've dialled in a small test OC up to 2.75GHz by winding up the FSB, ratio still at 1:1, and all seems well. To push this further do I need to change anything or just carry on as I am? Do I need to set the CPU voltage manually?

Temps seem OK, in RealTemp at idle I get:

core 0: 37
core 1: 36 (this one is stuck and never budges even under load)
core 2: 30
core 3: 27

Under load (3 hours of prime 95 - four threads) these get to 49 for core 0 descending to 40 for core 3. The stuck sensor is annoying but if I use core 1 as my benchmark I should be OK?

If I can get to 3.0 - 3.2GHz I'll be happy!

Any advice would be very welcome!
 
Firstly, manually set the CPU voltage to 1.235v. Then set the PLL, FSB Termination and Northbridge voltages to +0.02v above their lowest non-auto level (PLL - 1.52v, FSB Term - 1.12v, and NB - 1.12v). The board seriously over-volts the three main chipset voltages if left on Auto or the lowest non-auto setting.

The default 1.235v CPU voltage should be enough to get you too atleast 3.1ghz.

Also be sure to update to atleast BIOS 0704. And do this from a CD or USB flash drive from within the BIOS rather than using the Windows BIOS flashing utility (it's infamous for killing boards).
 
Cob said:
Firstly, manually set the CPU voltage to 1.235v. Then set the PLL, FSB Termination and Northbridge voltages to +0.02v above their lowest non-auto level (PLL - 1.52v, FSB Term - 1.12v, and NB - 1.12v). The board seriously over-volts the three main chipset voltages if left on Auto or the lowest non-auto setting.

The default 1.235v CPU voltage should be enough to get you too atleast 3.1ghz.

Also be sure to update to atleast BIOS 0704. And do this from a CD or USB flash drive from within the BIOS rather than using the Windows BIOS flashing utility (it's infamous for killing boards).
Click to expand...
Thanks for the rapid reply. I have already updated to 0704 - quite like the flash from USB stick facility - beats a floppy any day! I never trust Windows BIOS flashing utilities, so no worries there.

I'll set as you advise and start winding things up - thanks very much!
 
BIOS set as advised, running at 2.8GHz for a bit now. Happily core 1's sensor is not totally stuck - it did rise last night above 36 degrees under prime95 testing, it just doesn't drop below 36 degrees when idle.

CPU-Z is showing core voltage as 1.216V, I set it to 1.2375 (VID) in the BIOS. Do I need to add a bit more to make CPU-Z show 1.2375, or is this OK?

Thanks!
 
Nah that's ok. It's normal for the vcore to be less in Windows than is set in BIOS.
 
As I'm most likely going to be running my RAM at or under SPD, even up to 3.2GHz if I get there - is there any mileage (or is it possible) to lower the CAS down to something like 4-4-4-15 instead of 5-5-5-18? Don't know how good this Corsair stuff is like in that respect, I've read it'll do 1000 but that's not on my horizon!

Thanks...
 
Cob said:
No idea tbh. It's something worth testing tho.
Click to expand...
Well, easily got to 3.0GHz without upping vcore past VID, 9 hours Prime stable. Peak temps over the 9 hours (as per RealTemp) as follows:

Core 0 58
Core 1 49
Core 2 53
Core 3 50

No idea which to believe, but they are all within safe limits.

Thanks for yoir help Cob!
 
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