On 2004-04-01 bouyer@antioche.lip6.fr wrote:

> sorry for the sighly off-topic question, but I don't know where to find
> this kind of information ...
> I have a dual-PIII on which processes occasionally core dump while doing
> a ./build.sh -j4.
> mbmon reports the following values, and I wonder if they're out of range
> or not. I find the +5V and +12V a bit low.
>
> While idle:
> Vcore = 1.79, 1.76; Volt. = 3.32, 5.00, 11.65,   0.00,  0.00
>
> with both CPU running a while(1):
> Vcore = 1.74, 1.72; Volt. = 3.29, 4.91, 11.83,   0.00,  0.00
>
> Runnig a tar cf from local disk to /dev/null in addition to the 2 while(1):
> Vcore = 1.74, 1.70; Volt. = 3.29, 4.88, 11.83,   0.00,  0.00
>
> I should probably get the real values with a voltmeter, but I'd like to
> also know the range of acceptable values.

  I think +/- 5% is the usual good range (hardware datasheets should
always have the values.  Documentation provided with the product should,
but often does not).  My Athlon-XP system shows 11.86 on the +12V during a
kernel build via the MB while the DigitalDoc shows dips down to 11.76 (I
do, however, have two variable rate fans that could help cause this).  My
+5V is shown as 5.07 by the MB and generally around 5.11 by the DD.  I
have not had any hardware problems with this system.  It is possible you
could get occasional dips below acceptable values.  IIRC, PIII did not yet
use +12V for the CPUs, so +5 is more likely to be the problem if it is the
power supply.  Some power supplys also have a maximum combined +3.3 and +5
draw less than the individual ratings.  And many power supplys perform
significantly less than than their spec says.

Matthew Orgass
darkstar@city-net.com