[ntp:questions] improving ntpd performance on Windows

Martin Burnicki martin.burnicki at meinberg.de
Thu Mar 5 13:59:53 UTC 2009


Dave Hart wrote:
>> Unfortunately under W2k the new code does not seem to work as good during
>> the first minutes after startup
> 20000 seconds is 5.5 hours, the length of the roller-coaster ride it
> took as I read it.  I see inflection points which I'm guessing are 512
> seconds apart where the counter frequency estimate was changed.  I'd
> like to see the ntp.log or event log entries for the first few hours
> of that w2k run, if available.  I'm particularly interested in the
> (frequent) messages showing the ctr frequency observations and running
> average.

I'll send you the event log file and the raw loopstats via private mail.

> Meanwhile, I've been whacking on this code more to try to get cleaner
> samples to begin with by using a separate timer and callback (though
> same thread) for managing the counter frequency, and by starting out
> with the history of observations effectively filled with the nominal
> performance counter rate, so the adjustment starts happening after one
> period (currently testing 512 seconds again after many tests again
> with smaller periods), albeit at a moderated rate.  After the first
> period, with a depth of 4, the rate used is the average of one
> observation and 3 nominal rates.  After two, half from observation and
> half nominal.  Those change might affect this behavior.
> I'm much more interested in the w2k improvements than vista.  The
> blunt object fix of using the native clock is boring and hasn't needed
> any fine tuning ;)

Yes, it works really great!

Martin Burnicki

Meinberg Funkuhren
Bad Pyrmont

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