Upper Vcore limits for 3.0 Northwood

I have been able to get this chip up to 3.6 stable, but beyond that I get random crashes after about 2-3 mins. I notice that under load my mobo drops the Vcore supply down to about 1.55V. So I was wondering how safe would it be to push more voltage beyond 1.6V into this chip?

Has anyone else managed to get this one higher at the 1.6V?


S Code: SL6WU
Plant: Malay
FPO: M41013613

it's not really advisable to go much past 1.6v, though many have run 1.65v for extended periods.

So is ok to leave the chip at 1.6V for extended periods?

Yep pretty much just make sure it isn't flying everywhere in windows. But I wouldn't really go much higher with the vcore after 1.6 maybe to 1.6125 but that's it. That's still a nice OC for a NW chip.

PEACE

1.6v max 24/7 on air or water.

Id condiser slightly higher on sub zero temps.

I guess that I must be a little bit extreme then with respect to vcore, but I've always used 1.7v as my max for extended use and even more for short terms, granted, monitoring temps along the way.

I used to say 1.7v max for Northwoods, but I've heard about too many that were fading at that voltage. Now I say 1.6v to 1.65v max depending on cooling.

Ran my P4 3.06GHz at 1.675v for almost 2 years without any problems before upgrading.

My 3.4C is set at Auto and not overclocked...Asus probe reports 1.616 at idle.

My other system is a Pressy 3.4 at 3.85 and asus probe reptr 1.312 at idle, even though the voltage is set at 1.4 in bios.

So I guess if probe is close 1.6 isn't the absolute max, but I'd trust the opinions of these guys and stay away from 1.7 long term.

Shane

lol
long story short, i happened on this thread and the one i'm about to direct you to by accident

3.0c overclocking problems

I had a similar setup and found that 3.6Ghz@240Mhz (ADATA ram DDR500) was the max i could reach (stable) regardless of what i did but my cpu voltage was 1.575

now i still have the same mobo as you, corsair twinx1024-4000 coz i though it was the ram, upgraded to a prescott 3.4Ghz cpu which is water cooled with the TT big water, 2x 36Gb raptors in raid0 and a 9800xt.
with the new chip i couldnt get over 236Mhz stable and with the new ram, 220Mhz was too difficult.
I have now removed the raid array and done a few other things and think now thats it's GAT that is stuufing up the settings.
I changed my multiplier to 12 and the FSB to 100Mhz and run the os, then put the multiplier back to 17@240Mhz and now it's stable yet b4 i did that, yhe prescott wouldnt go over 220Mhz.
set ya GAT (game accelerater) settings to Turbo-A-A-D-D and if that works then ya get good ram bandwidth with your 3.6Ghz overclock, thats what i settled for when i had the northwood.

these boards do seem to massively undervolt though, luckily, i have mine set to 1.482ish and it is acually 1.39v (prescotts max at 1.55v instead of the northwood 1.75v)
hope i havent sent any one to sleep yet

I wouldnt go much higher than 1.6 or your northie could die early. S.N.D.S, its called

i forgot to add, heres a link to a thread i posted when i had trouble with the new ram corsair help
it basically goes through the steps of what i did and what i have found out.

i now reacon that between the GAT and my PSU being too small along with using too much power from the mobo instead of the psu directly has been the problem.

so try a few different things and see what you come up with

Lowered Vcore to 1.575 in BIOS (now reporting 1.536v in CPU-Z)
Changed GAT to T-A-A-D-D
Changed RAM timings to 2.5-3-3-5
Changed PLL to 247

So far Prime95 has run stable for 45 mins!

3.0 @ 3.7 on 1.575V

I think it was the memory timings (2-3-3-5) and/or the GAT settings that was keeping me from pushing above 240. I'm going to try and get to 250 this weekend, so I'll post my progress (if any) as I go.

Most likley.

I run A-A-A-D-D for GAT settings at anything over 225 FSB.

I don't fault anyone for choosing to use less than 1.7v. One of those things where you've got to go with what you are comfortable with.

my 2.4c idles around 1.61-1.625, and under load it goes to 1.55-1.575ish.

i've never had stability problems in the time i've had it (quite a while now, ever since the sl6z3's came out).

the snds cases i've seen/heard of have ONLY been at 1.675 or more, and in cases where the bios was SET under 1.7, the board usually overvolted at idle, causing it to exceed 1.7v.

i'd say you are perfectly safe if you keep your vcore as reported by mbm5 at 1.65v or less at all times, meaning at boot, at idle, and under load.

i've found that o'clock stability comes down to mobo, PSU and addition al devices attached.
i could never get above 240Mhz stable but then the ram i was using was part of the problem, my new ram voltage doesnt fluctuate as much with a highier voltage (2.8v) but the mobo is feeding .25v more than bios preset, so keep that in mind, the Prescott voltag is set to 1.468v (i think) but speed fan reads it as 1.42v, but i've noticed on the voltage graph that it can peak to 1.46v. I've pointed all this out cos even though the os may read lower than the bios setting on the IC7-Max3, keeep in mind that the bios voltage may be the peak setting and thats why Abit boards appear to under volt (safety for the CPU).
I've also noticed that if GAT has been changed, it may take a couple of restarts be for the settings completely reset, i.e. set timings for ram max then adjust GAT and restart then change again and restart then the stability may not be as good as last time you used those settings, restart twice more and they should be fully working (i think it's coz of the auto settings adjusting automatically to work with your setup so it will take time for them to change again)

no matter what, just remember that i'm a newbie too and am only telling you all what i have noticed, i have no computer background at all and am commenting on things i have read as well. but personally, keep the CPU voltage below 1.625v coz the 3.0 northwoods have a good rep with overclocking with out the highier voltage.

good luck and watch those rail voltages carefully (they could indicate a struggling PSU or voltages that are spiking too much)

My SL6WU box says "1.55v MAX" I would run 1.57v because with my droop under load I would be at 1.52v, which is what I think of as being the preferred northwood voltage. At that voltage I was able to reach my max overclock which is in my sig. I've gone upto 1.65v during tests, but it didnt help me at all, if anything it made things worse. I would say upto 1.57v actual voltage on normal cooling.

Foxie3a said:

My SL6WU box says "1.55v MAX"

Click to expand...

My 640 box says max 1.4v, heck default is 1.375.

I don't listen to max voltages. Just don't take it too high.

{PMS}fishy said:

My 640 box says max 1.4v, heck default is 1.375.

I don't listen to max voltages. Just don't take it too high.

Click to expand...

thats becuase you have a prescott not a northwood CPU

right click and "save target as"
875 pdf file info page 143 "absolute maximium ratings"
northwood pdf file info page 23 "maximium ratings"
Prescott pdf file info page 21 "absolute maximium and minimium ratings"
865 pdf file info just power ratings here

pretty much the above say that the absolute maximium for both the chipset (875) and the northwood CPU's is 1.75v, that includes voltage spikes, so if you had a spike of 1.8v then you may want to buy another mobo and cpu, maybe.
while the prescotts are alot lower, 1.55v.
the maximium rating on the box is the intel safe max rating, anything above that is not advised and may shorten the life of the CPU.

this should be enough info to keep you up all night and also to aloow you to know your cpu and chipset well enough to know what you are and arent doing.

i would suggest to keep below 1.6v for the northwood and below 1.46v for the prescott, even with water cooling. unless you dont mind buying another CPU.