Q6600 on P5K Pro = junkyard? unstable, PLL

[Kyo`]

OK, I got this nasty problem. Got my Q6600 L737B393 (VID 1.2125) and ASUS P5K Pro recently and I can't really get stable results here. The only stable OC I managed to get is on these settings:

Frequency: 8x450 (3,6ghz)
CPU Vcore: 1.4125v (bios), 1.36v (cpu-z under prime)
CPU PLL: 1.7v
NorthBridge: 1.65v
SouthBridge: 1.2v (max)
FSB Termination Voltage: 1.5v (max)
Clock over-charging: 0.9v

RAM is not an issue here, tried different straps etc, voltages are fine, still I can't get any other stable setting except for the above.
This is really stupid, I can prime on these settings for a few h no problem, and when I try to lower the fsb (while not changing anything else) to let's say 8x400, I'm not stable anymore! Actually I restart right after booting to Windows lol. I don't know what's the problem here, the only thing I can came up with is that this motherboard = junkyard quality
Anyway any change in the settngs above = restarts, underclocking the PLL from 1.7v = restarts. And here we come to the question about PLL, is 1.7v actually safe for 24/7 usage on the Q6600?
Any ideas what to do besides upgrading the mainboard?

Any help appreciated

[Solarfall]

hmmm well you could try a different bios and see if that helps

[Kyo`]

I'm on the newest BIOS, 806, it's supposed to be the best one... The original 0.501 or whatever was tragic, the mainboard did some crazy things, like triple-bootings etc.

[ZOMGVTEK]

I have my clock overcharging at .7, and PLL and whatnot are ALL at as low as they go, and im stable at 3.6 with my 1.300 vid Q6600. Set all your settings at the bottom to as low voltages as they go, and a .70 clock overcharge, and you might need to up the voltage on the processor, it takes 1.5625 in bios for me to be stable. And im running my ram at 1000, 1.95V

[Kyo`]

I tried doing lower voltages on PLL etc, while bumping the vcore as high as 1.4v on load. Still I did not get anything better then priming for a few seconds b4 restarting, not to mention stability.

[Gen]

how do you know it's not your cpu? is your Q6600 a G0? b3's are harder to clock. can you try it on another board?

it seems unusual that any change to your voltage settings would restart at 8x400. it seems you have played with settings alot so forgive me if you covered something listed below.

sometimes higher voltages cause less stability, intel has stated 1.6v pll is max for Q6600 for 24/7 if you believe them

on my Q6600 1.5v FSB equaled instability at any o/c while others were using higher, all cpus are different maybe try 1.4v with ram 1:1 @55515 for 8x400. also try with perfomance lvl on relax lvl 3.

you could check too see how good the contact is between your nb/pmw sinks, although if your stable at 8x450 it would lessen the chance if this being the cause.

maybe a bad flash occured. did you load defaults,flash, then reset cmos? or try another bios?

the only way to rule one or the other 'junkyard' is to try your cpu in another board. 8x450 is by no means a bad o/c (that's my current o/c) and i could care less about 8x400 is there a specific reason you need 8x400? or did you want 9x400? anyway i hope you get it sorted out.

[Kyo`]

Well, I need to do something about the PLL. It seems a little 2 high, I don't want to end up with frying my cpu someday.
My Q6600 is G0. The only board I can try it on is Gigabyte DS3R, but that 1 has a really poor bios and there's no way to even set the PLL there. So it might as well put it automatically on a high value being stable and I won't even know about it.

[Cronos]

I have several P5K-Pro with Q6600 G0, 3.2 -3.6GHz.
Runs perfect, with recent 0806 BIOS.

All voltages manually set to default (lowest possible) values, GTL Ref on auto, PCI-E to 100.

I don't need to change anything but Vcore and Vdimm. For 3.6GHz, Q6600 G0 requires 1.4 -1.42V actual, under load (Linpack 64). On this board, this requires setting vCore in BIOS to 1.47 -1.49, idle Vcore will be 1.44-1.46.

I have tried FSB upto 480MHz, stable, and still don't need any increase in voltages besides Vcore and Vdimm.

[Kyo`]

What is your CPU PLL then? If it's on auto, the mobo might aswell push it on a high value anyway.

/edit
Anyway, the settings I posted crashed after some more priming. ATM I have set:

vcore: 1.4v load
cp pll: 1.6v
fsb: 1.45v
nb: 1.59v

Priming for 20mins now, gonna see if it's stable... But tbh, that's some serious voltage there on the vcore.

[Cronos]

All voltages manually set to default (lowest possible) values

***

[Kyo`]

Yes, but how do you know which are "default" values? I don't really understand what you mean by this.

[Gunlance]

Have you tried more vcore? My 2 GOs need at LEAST 1.525 in bios to be stable at 3.6

[Cronos]

Yes, but how do you know which are "default" values? I don't really understand what you mean by this.

BIOS tells you , just look at the comments to the right. And if you cannot lower the value anymore, its the lowest possible . I leave Overcharge Voltage on the auto though.

[jonny_ftm]

I'd fix the vcore to 1.45v first, PLL to 1.6
Maybe you're just shooting too high for your CPU. The P5K Pro has very good overclocking reviews with a Q6600

[Kyo`]

Well jonny I tried that 2, but it just wasn't stable. In fact, I couldn't get stable no matter what anymore even for a short time! So I got pissed off and removed the board, installed my old DS3R, and...

I'm currently priming a few mins on 3,2ghz (8x400) with a voltage of... 1.25. And everything seems to be fine. Problem is, in this board you don't have even half of the options from P5K Pro, so I can't set PLL or GLT etc.
So now I think I'm left with 2 options: either the P5K I got was damaged or the DS3R is pumping so much PLL in my cpu that it's stable but will burn in 2 weeks :P Well, dunno really, I've seen quite a lot ppl running Q6600 on this board and they were fine. And tbh, even with a high PLL on the P5K i wasn't stable after like 2h of prime.

[jonny_ftm]

If you can't set PLL, than it won't be bumped
Was the P5K Pro stable on stock settings? If not, it could be really a bad board in fact

[Kyo`]

OK, the P5K I got is damaged, that's the only explanation I have. I was testing various options, every combination possible and couldn't gain stability. Don't know if it was stable on stock, didn't prime for a longer time on it. But on my DS3R I'm now running 3,4ghz (8x425) on 1.264v and it's stable for 1h now and I have a feeling it will stay that way.
Anyway, time to RMA the board then... if it's possible I'll throw in some cash and swap it for a Maximus Formula

/edit
3h hour priming stable for now
I'm gonna leave the bastard overnight, hopefully I'll keep the stability for a nice 8/10h+. Time to hit the sack.

[jonny_ftm]

OK, the P5K I got is damaged, that's the only explanation I have. I was testing various options, every combination possible and couldn't gain stability. Don't know if it was stable on stock, didn't prime for a longer time on it. But on my DS3R I'm now running 3,4ghz (8x425) on 1.264v and it's stable for 1h now and I have a feeling it will stay that way.
Anyway, time to RMA the board then... if it's possible I'll throw in some cash and swap it for a Maximus Formula

/edit
3h hour priming stable for now
I'm gonna leave the bastard overnight, hopefully I'll keep the stability for a nice 8/10h+. Time to hit the sack.

Think at it twice before you get the maximus...
The DFI LP X38 or the new X48 are worth considering. Have you read ASUS maximus thread?

[Kyo`]

OK, the CPU passed the stability test As for the ASUS Maximus Formula, well it's the only decent board in this crappy store, they don't have DFI's on x38. In fact the best DFI they have is the Iron Blood P35.

[ZOMGVTEK]

If you still have problems, i can give you my config settings file, or just tell you all the settings. you have speadspectrum and c1e off and whatnot?

[Kyo`]

Yes ofcourse I had those off. I'm just gonna RMA the board, it's clearly damaged, since now I'm running 3,5ghz on 1.264v stable on a DS3R.

[Kyo`]

OK, I can choose from the following boards (only decent ones in the store):

1) ASUS Maximus Formula
2) DFI LanParty UT P35-T2R

Any feedback? I'm thinking the LanParty myself.

[jonny_ftm]

Depends on your needs:
- True Crossfire needs the X38
- Also X38 adds PCI-E 2.0, but useless even on a dual GPU card, so won't be used before end of year maybe

DFI P35 would give you more stable and less trickier overclock expierience for a better price

You have to decide on those infos

[ZOMGVTEK]

It takes 1.5v in bios for my Q6600 to be stable for hours... You likely need more voltage on the core. You can just throw 1.55 at it. If it primes for 5 mins, thats probably stable-ish compared to your several seconds. Then you know it just needs more voltage. Then drop it down until you think its as low as it goes... prime for a few hours... etc...

[dnottis]

It takes 1.5v in bios for my Q6600 to be stable for hours... You likely need more voltage on the core. You can just throw 1.55 at it. If it primes for 5 mins, thats probably stable-ish compared to your several seconds. Then you know it just needs more voltage. Then drop it down until you think its as low as it goes... prime for a few hours... etc...

agreed, 3.6 with mine takes 1.43v actual under load. I think his problem all along is not enough voltage.