[ntp:questions] Meinberg NTP monitor, silly question

unruh unruh at wormhole.physics.ubc.ca
Tue Dec 22 18:31:39 UTC 2009

On 2009-12-22, Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
> David J Taylor wrote:
>> "G8KBV" <g8kbv at nospam-uko2.co.uk> wrote in message 
>> news:MPG.2599f4f8b90958d1989692 at news.demon.co.uk...
>> []
>> You will find that for the best performance, the NTP PC needs to be left 
>> running, as initial settling is not quick.
> "Not quick" is an extreme understatement!  It takes about 30 minutes to 
> get a "reasonable approximation".  It can take ten to twelve hours to 
> stabilize with the best possible approximation of the time.  Once there 
> it's good for as long as you can keep the power on and the temperature 
> reasonably stable.

Yes, the time scale is about 1 hour half life (it takes about 1 hour to
halve the error). David Mills gets really
annoyed if someone points out how slow ntp is at converging. It is
definitely a feature, not a bug. That you or I could, with the first
three offset measurements, make a far better approximation to the true
time and rate than ntp does, is irrelevant. 

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