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Vcore & voltages going up & down

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Jan 22, 2001
When I startup the Via Hardware Monitor System V2.04,
and I look at the Vcore value, i see it going up and down
sometimes, from 1.82 to 1.81 and back....
This happens even when i do nothin at all.
I just start up the program, and watch it.
What does this mean? Is my psu to weak? Can this be a bad thing,
or maybe cause crashes? Or is it just the via-program that isn't perfect?

Also, when I i.e. klick on a window, and move it around a bit,
i see the 5V value goes from 5.09 to 4.98-4.95V, and i can hear my
120mm fans slowing down a bit. (the sound changes)

If it is a psu problem, which psu can be reccomended?
Is the 330W enermax good enough, or schould i go for a bigger one?

I have a standard (no brand) 300W psu.
Tbird [email protected] with Alpha pep66+delta+arctic silver
Abit KT7A
Hercules gts2 pro 64mb
sblive+digital interface card
ISA scanner card SCSI
seagate barracuda II 20gb 7200rpm
pioneer dvd & sony cdrw
2 casefans 120mm at 7V and a neon light kit at 12V

Ps. I accidentally placed this also in the AMD CPU forum,
i'm sorry for this.... ;-)
I got the same kind of fluctuations with an Enermax 651. It just died. I don't remember them with my old 400 watt PSU. A new 651 will be here tomorrow. Will let you know what happens. Perhaps someone else can shed some light on this.
Assuming that Motherboard Monitor is compatible with your mainboard, see if the wandering voltage values are confirmed with it. 1/100th of a volt fluctuations aren't that unusual. Uninstall the Via monitoring program before installing MBM. And vice versa, of course.

If MBM confirms that the Core Voltage constantly changes, the problem may be with the mainboard's voltage regulator or the PS. Or both.
The 1.81/1.82 fluctuation is probably normal 1/100 of a volt is not that much, and it can fluctuate. Usually temperature differences in the case can cause this, and they cannot always be caught by the voltage regulator.

Regarding the drop in the 5V voltage, this is something new that I did not observe with Intel systems. Most likely this is a result of the massive power draw of the CPU, which runs off of the 5V lead. A 1200MHz CPU with 1.81V draws about 75W, that's about 15A. Look at your P/S and you may see that it probably has less than 30A to supply. If you use half of that on the CPU itself, it is likely that you will end up using a total of 23 or 25A. This bogs down the Voltage (just like in an old house the water pressure goes down when you use several fossets at once).

A solution is to get a better (i.e. stronger) P/S. Ideally get a P/S that allows adjustment of the output voltage. I have an Enermax 651, but the voltage still drops to 4.88 - albeit when I use 1.9V at 1350MHz or so. However, I have another real expensive P/S from PCPOWERANDCOOLING (was about $200 a year ago). This thing is rated at 425W, but it regulates within 1% and it allows adjustment of the output voltage. That baby basically lets me jack up the voltage to 5.2 or 5.3, and then comes down to 5.1 or so even when overclocking seriously.

I hope this helps

yea a .01 or .02 in voltage diff is normal but other is because of power supply being on the edge of its MAX

get a stronger power supply

i have 2 300 antec power supplys tied together @ the ATX connector and my voltage leveled out ALOT

and ALOT of my lockup problems STOPPED
Power supply is my guess.

You think yours is bad my 5v line is down to 4.88 and my 12v line is down to 11.58. Iv got a 350 watt enermax on the way though.
Thank you everybody,
i'm going to start looking out for a stronger psu.
(there goes my money again... :-( )
Unless your having stability problems i wouldn't spend any money on a new PSU. A variation of .01 is nothin, really. If it gets as bad as mine you might start havin trouble, my comp spontaneously shuts down at random.