NF7-S 2.0 vdd problem?

- Barton 2500+ AQXEA
- NF7-S 2.0 bios rev 18
- Twinmos/Winbond CH5 3200 ram (declared as cas 2.5 @ 200MHz)
- Thermalright SLK900U
- Radeon 8500
- memory timings are 6-3-3-2.5 (i didn't change timings)
- CPU interface enabled
- Vdimm @2.9V
- Chieftec 360W

With default vdd voltage (1.6V) i can only reach about 205MHz stable..
When i pump-up the vdd to 1.7 i can reach up to 215MHz.. but when i do so my Vcore becomes very unstable.. it jumps up/down for almost 0.08V causing CPU to be unstable at anything more than 2GHz

I Currently run at 11x200MHz (vdd=1.6 vcore=1.825 (bios) vcore~1.77(hwdoctor) ) and it is prime95 stable.

Why is there so much under-volting on Vcore?!
Shouldn't i be able to reach 2.4GHz with default voltage?

I would blame it on the PSU, or maybe your mosfets are getting hot toasty and need cooling to keep a stable V-Core... or maybe both...

mosfets are stonecold.

Also i doubt it's PSU.. i don't have many stuff conected to it.. and other voltages (than Vcore) are 100% stable.

I'm currently running at 10.5x200 (2100) with mem timings 5-3-2-2 and it is prime95 stable...

But still... i can't imagine why i wouldn't be able to run my proc at 2.3GHz +.

abit nf7s are known to undervolt alot...i set my vcore to 1.85, but fluctuates from 1.79-1.825 and somtimes 1.85...almost all my voltage lines are undervolted, and i got a trupower 480w...so yeah put up the vcore, vdd higher cuz it'll most likely undervolt...also if you want more fsb, u gotta up the vdd voltage using a resister or pencil mod found at www.motherboardfaqs.com ...i did it yesterday w/ a pencil for about 10-15 times, and i got 235fsb w/ 11-3-3-2.5 ram timings... good luck

i use to have the same problem with my vcore voltage being low and always jumping up and down. But i now have a 550w psu and now i get a rock solid vcore but it's still under volts though.

And last week i just built a new pc for my brother but with the newer abit nfs-7 ultra 400 board with a 400w psu which was my old one and with that setup it actually overvolts by around 0.01 to 0.02.

It looks like cpu interface feature was causing most of my problems..
I disabled it and my voltages are now solid.. Vcore going down by at most 0.01

I can now set vdd to 1.7 and get fsb as high as 220..

However.. i still can't overclock my CPU to anything higher than 2.2GHz. This is annoying.. maybe i just got bad piece.

Vcc voltage is Vdimm? Is my assumption correct?

Vdimm is typically the notation for RAM voltage. Chipset voltage is either Vdd or Vcc.

Apparently CPU interface thingie didn't work best either..

and with NF7-S 2.0
Vcc = Vdimm
tested and verified..

hatch said:

Shouldn't i be able to reach 2.4GHz with default voltage?

Click to expand...

Who told you that? The Barton 2500s are not known to hit 2.4GHz at deault voltage actually not a lot of them hit 2.4GHz at any voltage on air. Your seeing the impossible as truth.

Your experience with the VCore fluctuating is common with the current production line from ABIT. When you decide to overclock properly crank the voltages to as high as your cooling will allow & see what you get. Default votage overclocking is a step backwards when looking for maximum overclock.

You already voided your warraty anyways

"You already voided your warraty anyways"

Not at all.. i just load original bios.. and that's it.. noone will have a proof i overclocked it i can blame them they sold me bad cpu which burned for no reason

By overclocking it you already have voided your warranty. Overclockers.com doesnt support your actions. I hope you realize that you are cheating other consumers with bad RMAs. People that cheat are not welcome here.