HOWTO: Overclock C2Q (Quads) and C2D (Duals) - A Guide v1.7

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graysky

Senior member
Mar 8, 2007
796
1
81
No, it's not odd, it's due to the uneven nature of your chip's IHS assuming prime95 stress (does a very good job equally stressing each core). You can fix it by lapping. Re-read the guide's temperature management section for more and links.
 

Hakkattack

Junior Member
Feb 28, 2008
2
0
0
Hi guys,

First post at anandtech forum!

Firstly thanks greatly to graysky for the guide. I would never have dared overclock without a easy to follow guide like that.

Anyway I have;

Q6600 G0
Asus P5E (X38)
2x2Gb OCZ DDR2 PC2-6400 (800Mhz) ram
OCZ vendetta cpu cooler
Cooler Master Cosmos1000 case
Ati 3780X2 (vents heat out of the case)

So I did my first ever overclock. I basically followed grayskys case study and did 3Ghz (9x333), with ram at 667 (1:1). Initially I was very pleased with myself, system was stable. However I was using "auto" for vCore and some of the cores were @68-69C at load (prime95 small FFT test). So I next went to reduce vCore. This is where I'm a bit concerned. The lowest I can get it and run reasonably stable (over 4hrs prime95) is vCore at 1.34V in bios.

That gave me;

vCore CPU-Z 1.31 idle, 1.272 load (Speedfan gives same values)

idle CPU 35, cores 36-38
load CPU 63, cores 63-67

Well, that seems safe anyway, but reading grayskys figures (vCore 1.2625) for the same overclock, and reading other peoples vCores mine seems a bit dissappointing. Below 1.34v I get errors in prime95. At 1.30v I run prime95 and my system locks up straight away:(.
At vCore 1.31 I get an error in 1 minute and so on.

I realise every chip is different and there are lots of variables between systems, but should I be doing better than this. I guess my temps are still fairly safe?

I wondered if the voltage of the ram was an issue. In bios it says "auto" so that's not helpful. I set it to 2.00v manually (ram rated at 2.1v) to see if it helped but no joy (in terms of running the vCore lower). Timings are set 5-5-5-15 (ram rated to 4-4-4-15) Also I guess my MB has quite a big vDrop/vDroop. Does that have anything to do with it?

I've seen guys talk of "unlucky Q6600 G0's". Any suggestions/thoughts?


Sorry for the long noob post.
 

graysky

Senior member
Mar 8, 2007
796
1
81
@hakkattack - thanks for the kind words. 1.34 V in the BIOS seems a little high for a G0 actually, but as you pointed out, you might just have a poor overclocker. Vcore to the CPU is independent of your RAM vcore and timings; it's just a matter of getting a 'good' chip that happens to run with less signal-to-noise (i.e, a lower voltage).

I'd say if it really bugs you, return it and hope for a better one or just keep it and run it at a lower level (9x300 maybe) and a corollary lower vcore. You can lap the CPU if you plan to keep it, but that will only help lower the temps, not the vcore. Really, you want to find a "better" O/C'ing chip, that is, one that'll do 9x333 @ a lower vcore since heat production is mainly due to that.

The thermal limit for your G0 is like 72 °C or so as I recall, so you're temps are still under the danger zone.

As to your vdroop question, I dunno about that board. I'd say just google around for terms like "P5E pencil mod" or "P5E vdroop" etc. and see if someone discovered a pencil mod for the board. That still won't help w/ your load temps though.
 

Hakkattack

Junior Member
Feb 28, 2008
2
0
0
Yeah, maybe it's just my particular chip then. I read somewhere in Tom's or Anand forum that a lot of the latest Q6600 G0's have been a bit dissapointing.

I suppose at the end of the day Intel are selling a product that says 2.4 Ghz on the tin and I can still get it to 3GHz and run below 70C at full load so I can't see the grounds for an RMA. I mean compared to a Phenom it still overclocks brilliantly.

Oh BTW an anand article on the P5E deluxe points out a vDoop of 0.07v (which they were slighly dissappointed at). I don't have the deluxe version, but maybe it's similar for the P5E. Seems like a decent MB nonetheless.
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,044
3,524
126
ack graysky your sticky duration ran out.

Need to ask a mod to restick it. I ran into this a while back ago, and this thread still has important info.

Anyhow bump back so its visable.
 

blanketyblank

Golden Member
Jan 23, 2007
1,149
0
0
before I fry something can someone please tell me if these temps and voltages are ok?
I'm new to OCing as my previous boards were cheap ECS ones that came free with the cpu. Now I have an Abit IB 9 board since it was on sale. I'm using a Tuniq Tower LED, though it seems strange that turning it on full blast and leaving it on low doesn't seem to make much of a difference maybe 1 or 2 degrees.

Anyways I have the external clock at 333 mhz and the multiplier at 9 to get 3.0 Ghz.
N/B Strap CPU as CPU. (not sure what PSB 1066, 533, 800, 1033 are). DRAM Spec. I chose 533 since that says 1:1 next to it.
For Voltage control I have CPU Core Voltage of 1.3875
DDR2 Voltage of 2.30
MCH Voltage of 1.250v

The Ram timings I left on auto as I have no idea what to put into each field though my RAM is labeled 5-5-5-15 PC 2 8000 and according to CPU-Z the mobo put it at:
333 Mhz 1:1 CL 4 tRCD 4 tRP 4 tRAS 10 CR 2T
If anyone knows what the timings are for these Geil sticks please let me know.
http://www.ocmodshop.com/ocmodshop.aspx?a=327
In particular I don't really know what the last field tRC is assuming I put 5's for the other fields and 15 for tRAS.

My temperatures are about 40 degrees idle and 60 or so on load after about an hour running Prime95 according to core temp.

Please let me know if this seems sustainable. Otherwise it looks like I can run 2.7 stable at stock voltage of 1.26 something. There the idle temp is about 30 and load goes to 50.

 

Germonicus

Member
Dec 21, 2005
76
0
0
Time for a newbie OC question about my rig:

I managed to get my rig (see sig for details) 3.66Ghz stable for 2 hours on Prime95 BUT when I run CPUZ the speed fluctuates madly between 3645 (405x9 FSB) and 2430 (405x6 FSB). This is my first ever overclock and I'm unsure whether the variation in CPU speeds is due to something bad I've done,some problem between Vista 64 and CPUZ or if this is something to do with the power saving features of the E8400.

I'd be glad if someone could help me avoid any costly mistake I may have made :)

PS.While I'm here a question about RAM voltage: There was no voltage guide on the boxes my GeIL DDR2 1066 came in so I went onto the US website and the specs say the voltage is 2.4v,would anyone know if this is correct?
 

geokilla

Platinum Member
Oct 14, 2006
2,012
3
81
Originally posted by: Germonicus
Time for a newbie OC question about my rig:

I managed to get my rig (see sig for details) 3.66Ghz stable for 2 hours on Prime95 BUT when I run CPUZ the speed fluctuates madly between 3645 (405x9 FSB) and 2430 (405x6 FSB). This is my first ever overclock and I'm unsure whether the variation in CPU speeds is due to something bad I've done,some problem between Vista 64 and CPUZ or if this is something to do with the power saving features of the E8400.

I'd be glad if someone could help me avoid any costly mistake I may have made :)

PS.While I'm here a question about RAM voltage: There was no voltage guide on the boxes my GeIL DDR2 1066 came in so I went onto the US website and the specs say the voltage is 2.4v,would anyone know if this is correct?

You have Speedstep enabled in the BIOS. Just disable Speedstep and your CPU will run at 3.6Ghz 24/7.
 

Tullphan

Diamond Member
Jul 27, 2001
3,507
5
81
The OP stated his memory timings are 4-4-4-12-4-20-10-10-10-11 on his Crucial Ballistix.
Is there any benefit to having those lower timings...the ones after the 4-4-4-12?
I currently have my Corsair XMS2 running @ 457.9, 1:1 ratio, 4-4-4-12, but the last 5 are higher than the OP's.
 

graysky

Senior member
Mar 8, 2007
796
1
81
Originally posted by: blanketyblankFor Voltage control I have CPU Core Voltage of 1.3875
DDR2 Voltage of 2.30
MCH Voltage of 1.250v

My temperatures are about 40 degrees idle and 60 or so on load after about an hour running Prime95 according to core temp.

Does your chip require 1.3875 for 9x333? That honestly seem a bit high. Have you attempted to minimize the vcore as described in the guide? 2.3 V also seems excessive. My DDR2 is rated @ 2.2V but I run it at 2.1V just fine. You'll have to consult google with your part numbers to find out the specs.
 

graysky

Senior member
Mar 8, 2007
796
1
81
Originally posted by: GermonicusI managed to get my rig (see sig for details) 3.66Ghz stable for 2 hours on Prime95 BUT when I run CPUZ the speed fluctuates madly between 3645 (405x9 FSB) and 2430 (405x6 FSB).

PS.While I'm here a question about RAM voltage: There was no voltage guide on the boxes my GeIL DDR2 1066 came in so I went onto the US website and the specs say the voltage is 2.4v,would anyone know if this is correct?

That 9x to 6x is speedstep - as you pointed out it's a power savings feature that activates when the system goes idle.

As to your RAM question, I dunno. 2.4V seems high to me.
 

graysky

Senior member
Mar 8, 2007
796
1
81
Originally posted by: Tullphan
The OP stated his memory timings are 4-4-4-12-4-20-10-10-10-11 on his Crucial Ballistix.
Is there any benefit to having those lower timings...the ones after the 4-4-4-12?
I currently have my Corsair XMS2 running @ 457.9, 1:1 ratio, 4-4-4-12, but the last 5 are higher than the OP's.

The sub timings don't have a really big effect in my experience. You can test it out for yourself using superpi which is pretty sensitive to changes in memory settings. As I understand it, the 5th timing should be one more than your first. In other words, 4-4-4-12-5 (4+1 = 5). Beyond that, there isn't much official guidance.

The tech's at crucial told me the subtimings are board-specific, but they tend to not know what they're talking about.

I honestly don't know if my settings are optimal or not. If you are game, try the superpi experiment (16M or 32M) altering one of the substimings at a time and report back.
 

TheRyuu

Diamond Member
Dec 3, 2005
5,479
14
81
Well, I got sick of waiting so I just bought a Q6600. Installed it today, overall, I like it, a lot.

I hit 3ghz easily and I think I have more room to play too but I don't feel like doing anything else with it tonight.
I'm running the vcore at 1.27v, lower then my old E2180 yet with the same clock (3ghz). Not sure what a safe amount of voltage really is yet, but I figure I don't wanna go over 1.35ish, not sure what's safe with this chip.

For now, 333x9, tomorrow, only time will tell ;)

And my idle temps are about 30C and load temps about 40C through core temp, not sure if this is good or bad, but I figure if the OP is getting 60C under load, it's pretty nice. :)
 

Tullphan

Diamond Member
Jul 27, 2001
3,507
5
81
Originally posted by: graysky
Originally posted by: Tullphan
The OP stated his memory timings are 4-4-4-12-4-20-10-10-10-11 on his Crucial Ballistix.
Is there any benefit to having those lower timings...the ones after the 4-4-4-12?
I currently have my Corsair XMS2 running @ 457.9, 1:1 ratio, 4-4-4-12, but the last 5 are higher than the OP's.

The sub timings don't have a really big effect in my experience. You can test it out for yourself using superpi which is pretty sensitive to changes in memory settings. As I understand it, the 5th timing should be one more than your first. In other words, 4-4-4-12-5 (4+1 = 5). Beyond that, there isn't much official guidance.

The tech's at crucial told me the subtimings are board-specific, but they tend to not know what they're talking about.

I honestly don't know if my settings are optimal or not. If you are game, try the superpi experiment (16M or 32M) altering one of the substimings at a time and report back.

I don't think my bios had a 5th timing like that...I think it jumped from 12 (4th timing) to 38 (default setting) for the 5th.
 

Heller

Diamond Member
Jul 10, 2006
6,551
0
0
is it safe to run my quad q6600 @ 1.57v?

heres is my setup

Q6600+TX2 Paste+Tuniq Tower(things a behemoth btw)
Abit IP35-E
XFX 7900GT
WD 160GB SATA II HDD
Samsung Sata DVD-RW
Antec Neopower 500w Modular.
Antec P182 Gunmetal

it runs 3.4 all day long @ 1.475vcore.

but in order to run anything above (aiming for 3.6ghz) i need atleast 1.57vcore.

my temps never go higher then 72* but hover around 68*c (full load, sff prime 95 v25?)

I've also turned of C1E.

ram is at 1:1 (is that right?)

how am i doing so far? this is my first time with an intel build.
 

DSF

Diamond Member
Oct 6, 2007
4,902
0
71
I wouldn't run it over the 1.475 you've already got. Even if your temps are ok, excessive voltage can damage the chip over time.
 

graysky

Senior member
Mar 8, 2007
796
1
81
@Heller - look on processorfinder.intel.com -- I think the max is 1.5 V but I could be mistaken.
 

TheRyuu

Diamond Member
Dec 3, 2005
5,479
14
81
Originally posted by: Heller
is it safe to run my quad q6600 @ 1.57v?

heres is my setup

Q6600+TX2 Paste+Tuniq Tower(things a behemoth btw)
Abit IP35-E
XFX 7900GT
WD 160GB SATA II HDD
Samsung Sata DVD-RW
Antec Neopower 500w Modular.
Antec P182 Gunmetal

it runs 3.4 all day long @ 1.475vcore.

but in order to run anything above (aiming for 3.6ghz) i need atleast 1.57vcore.

my temps never go higher then 72* but hover around 68*c (full load, sff prime 95 v25?)

I've also turned of C1E.

ram is at 1:1 (is that right?)

how am i doing so far? this is my first time with an intel build.

Your voltage of 1.57 is a tad bit insane. I wouldn't exceed 1.45 volts if you value your chip at all.
Often times, the reason people can't go over ~3.4ghz is because of their north bridge voltage.
I had to raise mine to 1.41 (still safe) to hit my overclock as well as make my ram stable. (1.37 makes the ram stable, 1.41 is just insurance to get my overall overclock 100% stable.

I just hit 3.6ghz with my q6600. This is with 1.42v on the vcore, can probably lower that to 1.4v, not sure yet. Only other voltage adjustment was the NB (MCH I think?) voltage to 1.41 (3 steps up for me).

I love this q6600 :)
 

Heller

Diamond Member
Jul 10, 2006
6,551
0
0
never herd of raising the NB voltage. hmm

how do i do that? :)

edit: figured it out...

NB was raised to 1.41

going to stress test 400x9 now @ 1.47

1:1 mem


lets see if its stable
 

Heller

Diamond Member
Jul 10, 2006
6,551
0
0
nope, failed prime instantly.

how are you guys running 3.6 with such low vcore?
 

TheRyuu

Diamond Member
Dec 3, 2005
5,479
14
81
Finally got my q6600 @ 3.6ghz stable.
Took 1.45v to do it, 1.44 on the NB, and a notch up in the ICH and FSB voltage.

Overall though, shouldn't be TOO dangerous. I should be able to lower the vcore as well since I didn't realize that the ICH was causing instability at first.

I guess tonight will be a night for stress testing too see if I can get lower voltages.

On a side note, anyone else with a Abit p35 have trouble getting their ram to change from a 1:1 speed. I can't seem to get it to go higher.