[ntp:questions] NTPD can take 10 hours to achieve stability
David J Taylor
david-taylor at blueyonder.co.uk.invalid
Tue Apr 19 05:55:16 UTC 2011
> Thanks for all the great answers. Now for a harder question, how does
> the accuracy of the local clock source
> affect the accuracy of ntpd.
It also depends on the OS in use. Even with a timekeeping GPS (better
than a microsecond), Windows does not keep time as well as FreeBSD.
Compare FreeBSD: PC Pixie, Windows: PCs Feenix & Stamsund
In my experience, even given an accurate source (e.g. a PC syncing to a
FreeBSD stratum-1 server), the network performance may have a greater
influence that the performance of the reference clock, especially if that
network contains gigabit components, or off-site connections, wireless,
If you want the best accuracy, ensure your PCs have a serial port, and
pipe a pulse-per-second signal round your lab. NTP works well with that.
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