[ntp:questions] refclock on Windows graphs

Unruh unruh-spam at physics.ubc.ca
Tue Mar 17 21:21:57 UTC 2009

"David J Taylor" <david-taylor at blueyonder.neither-this-bit.nor-this.co.uk> writes:

>Unruh wrote:
>> Gads, those offsets are huge. And 3PPM variation is also pretty big.

>Dell 4400 hardware sitting in a non-temperature controlled environment - 
>warm in the day, cold at night.  I would happily accept five times the 
>jitter for a fifth of the offset!

Maybe when someone finally put refclock support into chrony you will have
your wish. It sounds like your temp changes causing rate changes on a scale
that ntp cannot properly cope with. (ntp is terrible at coping with
changes-- a purposeful design decision by Mills). I get about 3-5 usec as
average offset, but the freq changes are only about .1PPM , not 3PPM. The
room is not particularly air conditioned, but the temp variations over the
day are probably less than 5C not 20C.


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