P4 doesn't boot with Vcore > 1.6v

[SPivX]

When i OC my P4 3.0 to 4 Gig, i have to raise the Vcore in the bios to 1.625v. In windows, MBM gives me ~1.67v.

But, my PC doesn't POST above 1.6 VCore. What could this be? And what should be the correct voltage readings? MBM or BIOS?

many tnx!

SPivX:banana:

[althes]

what board are you using

[shigs]

Originally posted by SPivX
When i OC my P4 3.0 to 4 Gig, i have to raise the Vcore in the bios to 1.625v. In windows, MBM gives me ~1.67v.

But, my PC doesn't POST above 1.6 VCore. What could this be? And what should be the correct voltage readings? MBM or BIOS?

many tnx!

SPivX:banana:

if its a prescott m8 it wnt boot over 1.6v

[charlie]

let me guess....P4C800?? It's a known issue with that mobo and Pressies.... try an IC7/G/M3 mobo.

C

[keith77]

SpivX what 3.0 did you get? My board also doesnt like anything over 1.6volt. Although it does post cant seem to get anything stable over 1.6volts, when there seems to be alot more room available with this SL6WK Q series.

[Gamer]

P4C800 has this problem without a vmod.
same thing here.
got an IC7-max 3 with prescott, and it does 1.7 vcore without a problem.
http://www.madshrimps.be/forums/attachment.php?postid=63635

[SPivX]

Well, to start the CPU is not a prescott, it's a new Northwood :) i Will try 1.7 in BIOS to see if it boots that way.

[Jupiler]

If you have a P4C800, you'll have to do the drop mod, to get more stable voltages.
The boards overvolts by default, except once you pass 1.6V, then it undervolts pretty heavy.
I have the same board and had the same problems without the drop mod. After the mod, problem went away.

[SPivX]

will do the droop mod tomorrow and see if there are any improvements :D

[Stelios]

There are Cpus (In case Northwood's) that like , and Cpus that don't like voltage.
If you are lucky , you can get one that works with high voltage ...

I tried 7 Northwoods from November till January and 2 of them wouldn't post with anything more than 1.65V (watercooled)

So ... try to find another Northwood to test it ;)

[mion]

had the same problem with my p4c after drop mod I was really happy I went from fsb 225 to fsb 247 at 1.63v, I wish my Abit max3 had drop mod

[SPivX]

Well, i did the droop mod but there are some questions:

» the VCore fluctuation is still ~0.05v. I saw a guy on this board that had only 0.01v fluctuation. How did he manage?

» I can't seem to raise the resistance of the potmeter past 29 kOhm. Is this usual?

[FUGGER]

The prescott has over volt protection that prevents it from starting if the bios is set above 1.6v or higher. The spec stats it is supposed to be .2v over defaut vcore. Asus boards uphold this rule so they prevent over volting.

Bigtoe might know a way to disable this feature.

[SPivX]

Well i did some OC'ing and i got my 3.0 stable @ 3.9 with a voltage of 1.475 (default) + 0.075 (overvolt / droop mod) = 1.550v. But to get to 4 GHz, i need a lot more voltage. My NB is not actively cooled, just a heatsink and a big 120mm fan on the side of my case that blows on CPU, NB and VGA.

If i watercool my NB, would i reach 4 Gig more easily? the heatsink on the NB gets hand warm (not hot).

[keith77]

wow great results after the droop mod. wish i had the mod cause it takes my sl6wk 1.585 to be stable at 3.9 after defaulting to 1.475 also. i am having trouble getting over the hump also. good luck

[SPivX]

well, 4.0 is too high for my WC setup. Prime95 doesn't give me an error, the whole system just freezes. This is because of the heat, isn't it???

Maybe i'll put a waterblock on my NB, or build a waterchiller. Then i should be able to hit 4200+, i think.

[charlie]

4.0 on water is not a "given", in fact i think 3.9's pretty decent!

C

[mion]

Originally posted by SPivX
Well i did some OC'ing and i got my 3.0 stable @ 3.9 with a voltage of 1.475 (default) + 0.075 (overvolt / droop mod) = 1.550v. But to get to 4 GHz, i need a lot more voltage. My NB is not actively cooled, just a heatsink and a big 120mm fan on the side of my case that blows on CPU, NB and VGA.

If i watercool my NB, would i reach 4 Gig more easily? the heatsink on the NB gets hand warm (not hot).

How long is the prime running before it stops

[daniel_tin]

Originally posted by FUGGER
... Asus boards uphold this rule so they prevent over volting.
... In the reality Asusboard P4P.. P4C.. undervolted, if Bios over 1,6V adjusted...
It´s cool :cool:

Sisoft Sandra :
Energy dissipation of the CPU only 36Watt instead of 89W(Intel)
with 0,94Volt instead of 1,375V

http://www.overclockers.at/attachment.php?s=fullpage=1&attachmentid=55364

[daniel_tin]

P4P800, P4C800 with 2,4A Presscott

( Bios ) 1,625 to 1.95 ==> 0.9 to 1,1Volt ( reality )

[saper]

Originally posted by SPivX
When i OC my P4 3.0 to 4 Gig, i have to raise the Vcore in the bios to 1.625v. In windows, MBM gives me ~1.67v.

But, my PC doesn't POST above 1.6 VCore. What could this be? And what should be the correct voltage readings? MBM or BIOS?

many tnx!

SPivX:banana:
I had the same problem. First of all i used VID pins mod to solve this prod. and it worked well. But it was uncomfortable. So i've try my best to find out another way to solve. And i've been successful.
I think that must be a bug of Main. If i set it at 1.625v it did not POST. But when i set it at 1.67+v. It worked well.

[brwmogazos]

One thing i have noticed with the P4C800E unmodded is that when selecting 1.6V in the bios it goes to 1.66V straight away...

so your chip may not like that...its a prob with the board...


BUT...i didnt know that the board cant take prescotts....

I have done the droop mod in mine and i was thinking of testing a 3.4E D0

My stock Vcore is 1.616 -1.632V when selecting 1.525 in the bios....thats the minimum it pushes...

Does that mean i WONT be able to run prescotts stable with it?
No matter what? There is no way arround it?

[brwmogazos]

Anyone who knows then ^^^?

Dont wanna get a 3.4E and then find out i cant run it :)