Voltage Fluctuations on Asus A8N-SLI

[Andrew LB]

The CPU v-core has been pretty unstable on my Asus A8N-SLI (i hear the deluxe and premium both do the same), so i was looking into better mosfet cooling (which probably would have done nothing) but i figured it was either a bios issue or something hardware related and not heat related.

I'm currently running my Athlon 64 X2 3800+ @ 2.6ghz with 1.5v v-core but it is bouncing all the way up to 1.552v in Asus Probe to as low as 1.456 volts. Thats a huge fluctuation.

Where on this motherboard can i actually measure the true v-core with a voltmeter? Asus probe is notorious for not showing proper voltages, even some bios's are. I've checked the 12v, 5v, and 3.3v on the power supply rails themselves and they're all rock solid and just above the 12v, 5, and 3.3v specs yet Probe and the bios both say my 12v rail is slightly under AND they're fluctuating. If its an issue with the board itself not properly regulating the 12v line, thus giving improper readings in the bios and software based utilities, should I slightly crank up the 12v rail on my PCP&C TurboCool 510-SLI via the 12v pot on the power supply?

I've got excellent cooling for an air setup and under load my CPU @ 2.6ghz never goes above 44'c. I just don't want to risk frying anything since this is my first PSU with adjustable rails which i have not touched yet.

I'm hoping this is simply something that the techs at Asus can fix with a bios update but i think its an issue with the hardware itself. If anyone has an answer to this problem, please help me out.

Here is a compilation of screenshots showing the fluctuations as well as some other things.

http://www.kalionzes.com/computers/A8N-SLI_Volt_Fluctuations.jpg

[Pntgrd]

I have an A8N-SLI-Premium with an Opteron 165@2610@1.425v(bios). I notic the same fluctuations in vcore when at full load (Dual Prime) 1.425 bios shows as 1.45= in Asus Probe. It will go up to 1.46 and drop as low as 1.40 with no discernable pattern to the fluctuations. This is with a Fartron Bluestorm 500w. But like you, if you check the rails at a connector, they are steady, so I agree it has to be something on the m/b itself. CPU-Z shows the same fluctuating values although not at the same time. It does not seem to effect anything though, just looks funny. I was hoping it would go away when I switch to an OCZ PS 520w SLI that is coming with my 2nd 7800GT on Monday. Since you are getting the same with your PC P&C I now doubt it will go away.

[celemine1Gig]

Have a look at this and measure the real voltage:

http://www.xtremesystems.org/forums/showpost.php?p=1094989&postcount=2

Don't ever take software readings as real! They can be quite accurate, but most of the time they're way off.