My New Build and Overclock Results

[Kent10]

Hi All:

My new build is up and running. Thanks for everyone’s assistance in choosing parts and getting it together. I think the hardest part was getting all my programs and settings to my liking. I was a little disappointed that after loading a significant amount, I found out the default setting on the motherboard was PATA and not AHCI mode which would enable NCQ and hot plug. Supposedly the Raptor I am using runs better without NCQ enabled (single user) so I guess I am fine. I wondered though if I would have the option to turn NCQ off if I was in AHCI mode. I couldn’t find a setting for it on my old computer with my 74 Gig Raptor running in AHCI mode.

Now I am attempting my first overclock and want to make sure I am doing it correctly.

I have OC’d the Q6600 G0 CPU to 3.2 by using the following method and tests:

--Lowered the “system memory multiplier” to 2.5 (lowest setting).
--Gradually increased the CPU Mhz from 266 to 350. I checked stability using Prime95 version 25.4 (4 instances) for just a few minutes at each increase.
--Prime95 failed at 350 Mhz.
--I increased the CPU voltage one notch from 1.2625 (default) to 1.275.
--350 Mhz passed Prime95 after a few minutes.
--Raised to 356 Mhz.
--Prime95 failed after a few minutes.
--I kept raising the CPU voltage 1 notch at a time (5 times) until I got to 1.30625. It was stable for an hour or so.
--Changed “system memory multiplier” to 3 (I think) which raised memory Mhz to 1068 (close to 1066 spec) and manually adjusted the timings to 5-5-5-18 (specs).
--Prime95 ran for 2.5 hours before one instance of the 4 failed.
--Increased CPU voltage one notch to 1.3125
--Prime95 has been running for 8 hours without failing.
--Core Temp .95 temps at 8 hours of Prime95 are 57 55 55 57 max., sometimes less (right now they are 51 51 51 52). At idle I noticed they were in the upper 20’s.

Now I would like to overclock the memory. It is at 1068 Mhz and 5-5-5-18 timings. How do I know what the voltage is? Which program is the most accurate? Sandra Lite says 1.8v. Easytune5 Pro says 1.85 and Speedfan reports 1.87 under Vcore2 (I assume this is for the memory, is that correct?).

In the BIOS on my P35 DQ6 Gigabyte board it says under “DDR2 Overvoltage Control” that “Normal” “Supplies the memory voltage as required.” Does this mean I don’t need to change the voltage manually and that if I tighten the timings or increase Mhz it will automatically adjust the voltage as necessary. Or should I go ahead and manually adjust the voltage up to a max of .33 to get it to 2.2 (if Speedfan is correct) which is the max in the specs for the Crucial memory.

What would be the best strategy? Max the memory to 2.2 volts, leave the Mhz at 1068, and then tighten the timings to 4-4-4-12 or should I change the “system memory multiplier” to increase the Mhz but leave the timings alone. Should I increase the voltage immediately to 2.2 or should I do a little at a time, test it and only increase it if there are failures? Or should I set it to the max 2.2 and then come down until there are failures?

Thanks everyone. I am having a lot of fun with my first overclock. Kent

[Kent10]

One more question on something bugging me.

If I find that my Q6600 is 24 hour Prime95 stable at 3.2 and 1.3125v, should these values always work? So if I were to experiment with other settings I assume I can come back to these settings safely without having to test them again. I am running the newer version of Prime95 25.4. I see most use the older version but I think this one runs 4 instances at once. That is good for a quad core, correct. All 4 cores are at 100% in CPU Usage History. I am running the blend test.

Did anyone notice that the specs at Intel have changed for the voltage of the Q6600? I think when I looked a while back the max was 1.372. Now they have the max listed at 1.5. Temperature is the same for G0 at 71C.

Intel® Core™2 Quad Processor Q6600 - SLACR

Thanks!

[simple_inhibition]

thats a pretty nice overclock you have i personally would try putting 2.2v into the memory and tightening the timings up as much as possible, but thats just me. you would need one heck of a cooling system to be able to run 1.5v through a Q6600 although apparently intel says it can be done

[Kent10]

Thanks. Prime95 is still running fine at over 13 hours. I think I will let it go the 24 hours and tomorrow I will try the memory. I'll try as you suggest. If I have time maybe I can try a couple different settings and see which is best. The difference may not be noticeable anyway. Thanks again.

[fps justin]

a G0 Q6600 can do much more than just 3.2ghz! keep going. good job so far.

[Kent10]

Thanks for the encouragement. I may go upwards after I know I have a good 3.2. I don't want to overdue it though. I need this computer to do my work and I need reliability.

[Kent10]

I have an update. I have only briefly tested the memory and it seemed stable at approx 1200, 5-5-5-15 and 2.2v but I will have to do more extensive tests later.

With fps Justin's encouragement I am trying to go higher on the Q6600. I tried 3.4 GHz with 1.375v and Prime95 failed. I decided instead of increasing voltage more I would decrease the Mhz. I am down to 3375 and testing for stability.

I didn't want to increase the voltage past 1.375 which used to be the max voltage listed in the specs by Intel. See post above. Specs have changed to 1.5v max. Am I being too conservative . In CPU-Z it lists the CPU voltage as 1.328 and Speed fan and Sandra list it as 1.33v. Are these correct or should I trust the reading from my motherboard at 1.375? Temps right now with Prime95 running are approaching 60C.

Thanks, Kent

[Mr. Miyagi]

Originally Posted by Kent10

Thanks for the encouragement. I may go upwards after I know I have a good 3.2. I don't want to overdue it though. I need this computer to do my work and I need reliability.

It does not matter how slowly you go so long as you do not stop.

[Kent10]

Update:
I have come down from from my attempt at 3.4Ghz. I also tried 3.375 and 3.35 and I think I found 3.35 stable with 1.375v but my temps were sometimes at 70C so I decided to go for 3.3Ghz instead and now I am testing stability at 1.35v.

I also did some reading and the general consensus is that CPU-Z is not accurate with its voltage listing.

[Yellowhello]

Originally Posted by Kent10

I also did some reading and the general consensus is that CPU-Z is not accurate with its voltage listing.

Yep, that's what I found also. Best to check voltages in the BIOS.