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iBertus

Member

From: Greenville, NC

Registered: 2004-11-04

Posts: 2,228

Voltage drift w/ new mobo.

I just noticed that with my new Albatron KX18DS Pro nForce2 mobo (replaced damaged Epox 8RDA+) my Vcore readings in the Award BIOS pc health section show a value about .32V higher than my Vcore setting. Also, this value drifts around in a 16mV range above and below the value. It this normal. Power supply is a 480W Thermaltake w/ Smart Fans. Both are new as of this past Friday.

skoal

Member

From: Frequent Flyer Underworld

Registered: 2004-03-23

Posts: 612

Website

Re: Voltage drift w/ new mobo.

lmbo.  iBertus, I can tell you're itching to overclock this "puppy".  You're a glutton for punishment.  I like that.

If you've seen any variances between "default" core voltages and what the monitor is reporting, that's perfectly healthy.  All you're seeing is what voltage the CPU is fixed to run @ a set frequency.  You're health monitor is just reporting what's actually (to some degree of precision) being channeled into your proc.

When you start bumping up your core voltage to run @ a higher freq, I'd be willing to bet you will see that same difference in comparison to what it is at default settings.  That's just a measure of what degree of precision your motherboard design supplies the 3.3V from your PS.  My core V is ~1.5V +/-30mV drift, which is spot on, since the P4 requires 1.5V.  Later P4 generations probably need more since they run at higher freq's.

iBertus

Member

From: Greenville, NC

Registered: 2004-11-04

Posts: 2,228

Re: Voltage drift w/ new mobo.

Good to know that it's normal for the voltage to vary somewhat. I'm just used to my Epox board where the voltage readouts were pretty much right on what the settings were. Right now I'm running at 1.6V Vcore which is pretty normal for the Athlon XP range (1.65V std. for Bartons) but my voltage is always between 1.616-1.632. My guess is that the motherboard isn't that accurate at reporting the values.

skoal

Member

From: Frequent Flyer Underworld

Registered: 2004-03-23

Posts: 612

Website

Re: Voltage drift w/ new mobo.

Actually, that's only +/- 16mV, which is pretty good.

You know, I actually went back and read your top post.  I must have missed something.  You said that your default V for your CPU is set at ~1.6V, and the health monitor is showing it at ~1.9V? (the .32V you mentioned above).

On my Asus board, I have jumper free settings for CPU FSB/clock ratio.  I think the newer AMD XP's have either a 166 or 200 FSB, and mobos generally have a jumper for the FSB if not software jumper free in your BIOS.  If you set that correctly, and let the CPU use it's locked default clock timing, you should get a core voltage ~1.6V and the monitor should show +/- 15mV.  I don't know why your monitor would read +.32V from default core V, unless you already stepped up the clock or it's using the wrong FSB setting from a mobo jumper.  Check that out...