# Q6600 4GHz OC with my PSU impossible?



## Laurijan (Sep 7, 2008)

Hi all!

I am stuggling to get my Q6600 CPU to 4GHz.. i now can OC my rig to 3,6GHz@1.35V Vcore without problems and with my water cooling the temps stay low..

When i try to use 1.5V Vcore for 4GHz and even 1.55V Vcore i get windows stable but prime95 torture test (max power consumption) will crash my PC (blue screen, reboot) even though my temps stay low ~55C under load

Here are my bios settings for the 4GHz OC










I used the PSU calculator and it says that i need ~1000W for my rig configuration having 4GHz OC.. for 3600MHz is calculated ~750W as optimum which i have with my current PSU.. i dont trust the calculator even though i entered all specs into it the right way..

I noticed that under load at 4GHz my 12V rail droop from 11,9V to 11,83V and that i cant OC my GFX as high as before

Are these signs that my PSU is to weak?


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## Xazax (Sep 7, 2008)

only real way to try.. get a 1k Watt PSU :\ but are you jumping to 4Ghz? have you tried 3.7-3.8-3.9...


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## LionelHudz (Sep 7, 2008)

I would say it's your PSU. I've got the same problems. After i buyed a new one my system runs without problems.

Old PSU: 530 W BeQuit, 
New PSU: Coolermaster 850 W

You need more "pressure" on ther 12 V rail, my breaks down under Load like your's. Withe the new iv'e got everytime 12 V. System is a Q6600@3600 (Air) 1,48V and 8800GTX@Ultra.

Buy a new and all problems are history


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## Laurijan (Sep 7, 2008)

Xazax said:


> only real way to try.. get a 1k Watt PSU :\ but are you jumping to 4Ghz? have you tried 3.7-3.8-3.9...



I have had OCs from 3.7-3.9 but they were not stable in prime95.. only like for benchmarking with 3Dmark06 is used them.


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## JC316 (Sep 7, 2008)

Not likely your power supply, I have the same one and it's a beast, PLENTY of power for your setup. I would say that you just aren't giving it enough juice. There aren't that many 4.0GHZ Q6600's out there. I had to run 1.5V to get 3.8GHZ with my G0 Q6600.

The power supply calculators are WAY out of line, recommending more power than is needed.


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## Wile E (Sep 7, 2008)

JC316 said:


> Not likely your power supply, I have the same one and it's a beast, PLENTY of power for your setup. I would say that you just aren't giving it enough juice. There aren't that many 4.0GHZ Q6600's out there. I had to run 1.5V to get 3.8GHZ with my G0 Q6600.
> 
> The power supply calculators are WAY out of line, recommending more power than is needed.



Agreed.

That psu is fine for those voltages. I ran higher voltages and overclocks on my Q6600 and 8800GT with a 620W Corsair psu without problems.

You need to either try a lower OC with the same voltage, or the same OC with more voltage.


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## Hayder_Master (Sep 7, 2008)

I used the PSU calculator and it says that i need ~1000W for my rig configuration having 4GHz OC.. for 3600MHz is calculated ~750W as optimum which i have with my current PSU.. i dont trust the calculator even though i entered all specs into it the right way..

I noticed that under load at 4GHz my 12V rail droop from 11,9V to 11,83V and that i cant OC my GFX as high as before

Are these signs that my PSU is to weak?[/QUOTE]

i don't think so you really need 1000w , i think even 700w brand name like crossair will be enough , im PSU calculator too but it tell me need less than 400w , and you can see my system specs


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## Jansku07 (Sep 7, 2008)

PSU recommendations are crap, because they are made to ensure that even the sh*ttiest PSU will work with your system. A corsair HX620 will run almost everything that you throw at it, hell even a HX520 will do in most cases. Your PSU is fine with your system, the problem is somewhere else.


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## Laurijan (Sep 7, 2008)

Thanks for the answers but because the recommendations are so different.. some say psu no prob some its your psu.. i give the thread a bump


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## Sasqui (Sep 7, 2008)

Since you only have one video card, it's not likely you are reaching the PSU limits.  However, with a quad core CPU, it certainly is possible that the 4-pin motherboard connector is on a rail that is stressed to the max.

Remember the prescott EE (extreme edition) CPU?  It required the 8-pin CPU power connector.  I worked on a machine that would not run without it.  You've got 4 cores - not quite like running two seprate Core2's, but certainly eating much more juice.

It's also possible that you've simply reached the limits of the CPU, regardless of the fact it's watercooled.  Most of the processors I've OC'd didn't gain but a few .1 Mhz over air vs. water, even though they were loaded at only around 40c on water.


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## 3870x2 (Sep 7, 2008)

Laurijan said:


> Hi all!
> 
> I am stuggling to get my Q6600 CPU to 4GHz.. i now can OC my rig to 3,6GHz@1.35V Vcore without problems and with my water cooling the temps stay low..
> 
> ...



Ive never known someone unable to OC their CPU because of PSU.  Also, it is probably your ram.  Adjust your ram divider so that it sits at or near (+/-30MHZ) stock speeds, and up your voltages.  At that, you should be doing an mch of +.2 or .3.  Some people say they can do 3.8 on an e6750 on +.1, never works for me.

EDIT: im not sure that the Q6600 G0 can even go to 4GHZ stable in most cases....


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## Laurijan (Sep 7, 2008)

3870x2 said:


> Ive never known someone unable to OC their CPU because of PSU.  Also, it is probably your ram.  Adjust your ram divider so that it sits at or near (+/-30MHZ) stock speeds, and up your voltages.  At that, you should be doing an mch of +.2 or .3.  Some people say they can do 3.8 on an e6750 on +.1, never works for me.
> 
> EDIT: im not sure that the Q6600 G0 can even go to 4GHZ stable in most cases....



Bumb of me but what is a MCH?

Edit: I googled it and its North brigde volts..


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## Kursah (Sep 7, 2008)

Laurijan, may not help your OC, but will help stabilize your +12v, my DFI P35 Dark had the same vdrop on the 12v that yours does with a quad OC'd. 

There's a 4-pin floppy power connection near the top of the PCI-e slot area near the NB, if you can hook this up. It seemed to help level out my cpu vdroop a little bit, kept the +12v higher, went from 11.9 idle to 11.96, would not drop below 11.9v, and iirc the +5v stabilized also. This also helped to stabalize my GPU OC's too, but YMMV, it's worth a shot tho.

My Q6600 G0 was a trooper for sure, but took 1.42v for 3.6 in comparison to your 1.35v, it could be a chip limitation on the OC possibly? Can you attain 3.8/3.9 with stability? I'd drop to that and see what is attainable...I don't know how old/what batch your G0 is, but from what I've read the newer G0's released in 2008 have limits around the 3.4-3.8 range.

Hope that helps!


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## niko084 (Sep 7, 2008)

Your fine, your power supply is plenty powerful, but they do make a good point with the 4pin it "could" be limiting, but I doubt it to be honest, you have 2 12volt wires, that are capable of carrying 10amps each, 20 amps @ 12volts = 240 watts, your chip isn't going to take that much.


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## kyle2020 (Sep 7, 2008)

Jansku07 said:


> PSU recommendations are crap, because they are made to ensure that even the sh*ttiest PSU will work with your system. A corsair HX620 will run almost everything that you throw at it, *hell even a HX520 will do in most cases*. Your PSU is fine with your system, the problem is somewhere else.



very true. My HX520 will run my quad @ 3.8 / 1.45V all day long (if i wanted to) stable as hell. I can get it to boot at 4Ghz, but its not stable at all, even with 1.6V running through its veins. 

PSU isnt a problem, seeing as my 520W monster (  ) will run my system and a Q6600 @ 3.8. Its most likely the chip, i think ive been lucky and got an above average overclocker.


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## niko084 (Sep 7, 2008)

Ya to be realistic that power supply is big enough to run 2 8800gt's overclocked and that quad at 4ghz without an issue... lol


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## Laurijan (Sep 7, 2008)

Thank you very much guys i really am sure now it isnt my PSU after hearing all this experience you have


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## Laurijan (Sep 7, 2008)

Kursah said:


> Laurijan, may not help your OC, but will help stabilize your +12v, my DFI P35 Dark had the same vdrop on the 12v that yours does with a quad OC'd.
> 
> There's a 4-pin floppy power connection near the top of the PCI-e slot area near the NB, if you can hook this up. It seemed to help level out my cpu vdroop a little bit, kept the +12v higher, went from 11.9 idle to 11.96, would not drop below 11.9v, and iirc the +5v stabilized also. This also helped to stabalize my GPU OC's too, but YMMV, it's worth a shot tho.
> 
> ...



As you can see here i have connected the 4pin connector and the 8pin connector





I will try to OC my CPU not to 4GHz but 3.7 or 3.8 or even 3.9GHz


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## erocker (Sep 7, 2008)

Your CPU, NB, and CPU VTT need more voltage.


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## mrw1986 (Sep 7, 2008)

I can't get my QX6850 stable at 4ghz even with 1.5v in it. Very weird. Will run 3.6ghz ALL DAY but can't get 4ghz....


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## niko084 (Sep 7, 2008)

mrw1986 said:


> I can't get my QX6850 stable at 4ghz even with 1.5v in it. Very weird. Will run 3.6ghz ALL DAY but can't get 4ghz....



Are you serious, did you try dropping your multi, might need 1.55v also, unless your ram is an issue.


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## JC316 (Sep 7, 2008)

mrw1986 said:


> I can't get my QX6850 stable at 4ghz even with 1.5v in it. Very weird. Will run 3.6ghz ALL DAY but can't get 4ghz....



Just a limitation of the Kentsfield chip. 3.8 or 3.9 seems to be max for them.


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## niko084 (Sep 7, 2008)

JC316 said:


> Just a limitation of the Kentsfield chip. 3.8 or 3.9 seems to be max for them.



That's a bummer, I had my Xeon to 3.6 last night playing around, I was hoping this winter I could nail 3.8, but now I'm kinda worried.


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## Damian^ (Sep 7, 2008)

And if you cant get to 4GhHz, i wouldn't worry to much, that a pretty high overclock for the quads, i'v only seen a couple people reach that on early batches, latest ones usually clock out at 3.2Ghz others at 3.6GHz

Try working with your ram first and foremost


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## kyle2020 (Sep 7, 2008)

Damian^ said:


> And if you cant get to 4GhHz, i wouldn't worry to much, that a pretty high overclock for the quads, i'v only seen a couple people reach that on early batches, latest ones usually clock out at 3.2Ghz others at 3.6GHz
> 
> Try working with your ram first and foremost



i think i got lucky - mines from a late bath but she'll do 3.8 @ 1.45 24/7 - ive heard of people struggling to get over 3.2 nevermind close to 4Ghz.


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## Hayder_Master (Sep 8, 2008)

how much power your water cool system take


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## Laurijan (Sep 8, 2008)

hayder.master said:


> how much power your water cool system take



The pump is connected to a regular 230V powerplug and not to the PC but the 2 radiator fans are connected to the PC..


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## Laurijan (Sep 8, 2008)

kyle2020 said:


> i think i got lucky - mines from a late bath but she'll do 3.8 @ 1.45 24/7 - ive heard of people struggling to get over 3.2 nevermind close to 4Ghz.



I am now stable at 3.8GHz@1.45V, MCH is 2 notches up and VTT voltage one notch.. JUHUU


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## yogurt_21 (Sep 8, 2008)

JC316 said:


> Just a limitation of the Kentsfield chip. 3.8 or 3.9 seems to be max for them.



no, maybe some of the newer ones, but qx6850's are known to hit 5.2GHZ+ on the right cooling and 4.4 on water is rather common as well

for the q6600 certaintly most cap out at 3.8-3.9 but my q6700 has no trouble hitting 4GHZ on water and would go higher. now we'll see how it does on a water chiller (on my phase it breaks the 150w limit too easlity to clock it high enough to be worth it) 

knetsfields are good clockers, though newer ones have seemed limited by intel probabaly because thye want you to buy yorkfields. it always sucks to be your own competition. lol


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## Wile E (Sep 8, 2008)

yogurt_21 said:


> no, maybe some of the newer ones, but qx6850's are known to hit 5.2GHZ+ on the right cooling and 4.4 on water is rather common as well
> 
> for the q6600 certaintly most cap out at 3.8-3.9 but my q6700 has no trouble hitting 4GHZ on water and would go higher. now we'll see how it does on a water chiller (on my phase it breaks the 150w limit too easlity to clock it high enough to be worth it)
> 
> knetsfields are good clockers, though newer ones have seemed limited by intel probabaly because thye want you to buy yorkfields. it always sucks to be your own competition. lol



You just need to rebuild and retune that phase unit for quads. Should be able to get it to handle 250w at least. lol.


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## alexp999 (Sep 8, 2008)

Got to agree with everyone else. its not the PSU. Its most probably the top for the CPU. 
Whats the pack date?
If its a 2008 you should be thankful you got 3.6ghz, some top out at 3.2Ghz.
You'll need a 2007 pack date to get 4 Ghz.


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## Laurijan (Sep 9, 2008)

alexp999 said:


> Got to agree with everyone else. its not the PSU. Its most probably the top for the CPU.
> Whats the pack date?
> If its a 2008 you should be thankful you got 3.6ghz, some top out at 3.2Ghz.
> You'll need a 2007 pack date to get 4 Ghz.



The CPU was bought 9.11.07..


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## yogurt_21 (Sep 9, 2008)

Wile E said:


> You just need to rebuild and retune that phase unit for quads. Should be able to get it to handle 250w at least. lol.



time and money i don't have right now, I'll look into it for later, but right now the waterchiller is as easy as hooking the phase head to my gpu water block and running the watercooler as normal.


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## Tatty_One (Sep 9, 2008)

I have basically the same PSU and have two 8800GT's running in SLi, I also did that with a Q6600 overclocked but I could only get 3.8gig outta my old one   As plenty have said, dont put too much stock in PSU configurators IMO, bottom line is, a Q6600 at stock has a TDP rating of 95W, even at 4gig with a single 8800GT and the rest of your kit, you probably wont be pulling more than 500-550W  (Wile E's QX9650 has a TDP rating of 135W and at 4gig that gap would get bigger)........unless of course your PSU is faulty?


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## Laurijan (Sep 9, 2008)

Tatty_One said:


> I have basically the same PSU and have two 8800GT's running in SLi, I also did that with a Q6600 overclocked but I could only get 3.8gig outta my old one   As plenty have said, dont put too much stock in PSU configurators IMO, bottom line is, a Q6600 at stock has a TDP rating of 95W, even at 4gig with a single 8800GT and the rest of your kit, you probably wont be pulling more than 500-550W  (Wile E's QX9650 has a TDP rating of 135W and at 4gig that gap would get bigger)........unless of course your PSU is faulty?



Tatty i bought the PSU because you told me you get the same one (usually dont buy stuff before it is TPU approved).. nearly all experts i know tell me that PSU is fine and i believe so too.. its the CPU which needs more volt or isnt ocable to 4GHz or my loop is not strong enough.. time will tell winter comes and it gets -20C - -30C here in Finnland..


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## Tatty_One (Sep 9, 2008)

Laurijan said:


> Tatty i bought the PSU because you told me you get the same one (usually dont buy stuff before it is TPU approved).. nearly all experts i know tell me that PSU is fine and i believe so too.. its the CPU which needs more volt or isnt ocable to 4GHz or my loop is not strong enough.. time will tell winter comes and it gets -20C - -30C here in Finnland..



Damn if it's that cold with you in the winter I would want my chip running at 80C 24/7!!!


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## Jansku07 (Sep 12, 2008)

> .... even at 4gig with a single 8800GT and the rest of your kit, you probably wont be pulling more than 500-550W  (Wile E's QX9650 has a TDP rating of 135W and at 4gig that gap would get bigger)........unless of course your PSU is faulty?


 Well just today @ xtremesystems I read a post from a guy, that used 2 (two) heavily overclocked QX9775s and GTX280 with 550W peak power consumption.. Average was 350-450W. Here it is: 





> i was benchmarking a skulltrail setup with dual QX9775 CPUs overvolted and overclocked to 4.2GHz and GTX280 overclocked to max on air and the highest peak Wattage draw i saw in Vantage was 550W lol and it was mainly running in the 300-450W range really


Source


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## Tatty_One (Sep 12, 2008)

Jansku07 said:


> Well just today @ xtremesystems I read a post from a guy, that used 2 (two) heavily overclocked QX9775s and GTX280 with 550W peak power consumption.. Average was 350-450W. Here it is:
> Source



Yep, many people seem to want to over estimate power draw, however, they say, every system/PSU should have a 25% safety margin which sounds pretty good to me.


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## Laurijan (Sep 28, 2008)

I finally got my Q6600 to 4006GHz with my 750W PSU being no problem.. i had the NB voltage 2 notches up as well as the VTT voltage and the CPU core voltage was 1.535V


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## The_Real_DeaL31 (Sep 28, 2008)

i know its off topic, is it just me or people with intel cpu's have there vcore past 1.4v is considered way to high, but on the amd side 1.6v is ok


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## The_Real_DeaL31 (Sep 28, 2008)

like my old 939 athlon 3500+ san diego at 2.8ghz at 1.75v people might call me crazy but its still running fully stable


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## Kursah (Sep 28, 2008)

The_Real_DeaL31 said:


> i know its off topic, is it just me or people with intel cpu's have there vcore past 1.4v is considered way to high, but on the amd side 1.6v is ok



Well it depends on chip and cooling for voltage recommendations, especially because the higher the voltage you feed the chip, the way higher the temps go.

1.5v under good air cooling on a 65nm Intel Core2 is probably fine, you'll have heat increases from just the speed overclock itself, but the heat increase is substantial. 1.4v on a 45nm with good air is probably fine too, many say stay below 1.36v, but many run 1.4-1.45v on 45nm chips w/o much issue. Then you get into water cooling and beyond, many have found running higher voltages for more extreme overclocks attainable for pretty long term (1+ year(s)). Just depends on the situation really...nothing is guarenteed tho.


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## Wile E (Sep 28, 2008)

The_Real_DeaL31 said:


> i know its off topic, is it just me or people with intel cpu's have there vcore past 1.4v is considered way to high, but on the amd side 1.6v is ok



It depends. For 65nm Intels, the general consensus is that 1.5V is the safe 24/7 limit. On 45nm, the consensus is 1.4V

On AMD dual cores, it's usually 1.5V for 24/7 use.

Water cooling doesn't make higher voltages than those listed above any safer. They are architectural limits. Of course, there are some exceptions, because no two chips are the same, so your mileage may vary. 

I've personally killed 2 AMD cpus by running them at 1.55V (both on water), but I've seen others get away with 1.6V on air with no problems.


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## mikek75 (Sep 28, 2008)

Kursah said:


> Laurijan, may not help your OC, but will help stabilize your +12v, my DFI P35 Dark had the same vdrop on the 12v that yours does with a quad OC'd.
> 
> There's a 4-pin floppy power connection near the top of the PCI-e slot area near the NB, if you can hook this up. It seemed to help level out my cpu vdroop a little bit, kept the +12v higher, went from 11.9 idle to 11.96, would not drop below 11.9v, and iirc the +5v stabilized also. This also helped to stabalize my GPU OC's too, but YMMV, it's worth a shot tho.
> 
> ...



Thanks for the tip about the FDD power connector on the DFI Dark bud, never knew that was there, LOL


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## vega22 (Oct 13, 2008)

Wile E said:


> It depends. For 65nm Intels, the general consensus is that 1.5V is the safe 24/7 limit. On 45nm, the consensus is 1.4V...snip...



looks@ bios, sees 1.45v....o shit...runs away 

its horses for courses and wile is bang on the monies.


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## sneekypeet (Oct 13, 2008)

mikek75 said:


> Thanks for the tip about the FDD power connector on the DFI Dark bud, never knew that was there, LOL



It says in the manual its for multi card setups!!!!! Same as back in the times of the Ultra D's. Manual says it wont hurt to run without it!


I cant say it will hurt anything, but I have yet to see the need!


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## lilkiduno (Oct 13, 2008)

well i hope i got myself a decent overclocking chip. Q6600 recently bought


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