On 8/14/2009 11:46 PM isw spake thus:

In article ,
David Nebenzahl wrote:

Sounds OK to me, except that I just checked and reset my computah's
clock (I use a little Windoze utility called "NIStime" that gets the
time from NIST); it was off by about 5 minutes. Haven't synched it up
for at least 6 months, so I know my RTCC is at least that accurate.
(Running W2K, so I assume that no software process is adjusting my
clock.) Shouldn't most PC clocks be about that accurate? (Older MB,
forget exactly what, can find out if you're interested.)

Most crystals used in computers are within ten or 20 parts per million
of the frequency stamped on the case (you can get a lot more accurate
ones, but computers don't need it). AFAIR, those little cylindrical
"clock" crystals that run at 32,768 Hz are at least ten times poorer,
and far more temperature sensitive to boot. I think the *best* you could
expect from one of those without special treatment would be about a
minute a month.

Hope I'm not belaboring the point here. I just ran "net time" again and
got the error message "Could not locate a time-server". So I assume that
even if that process is running on my computer, as someone else here
asserted, it's not doing anything to my RTC, as there are no
time-servers to query (that it knows about). Therefore, the time my
computer displays is the actual RTC value. Therefore, it seems to be at
least as accurate as you've stated (about a minute a month), which
actually seems pretty damn good to me. If it gets off by 12 minutes a
year, resetting the thing once annually would yield a clock that should
be close enough for most folks' purposes.


--
Found--the gene that causes belief in genetic determinism