[ntp:questions] NTP vs chrony comparison (Was: oscillations in ntp clock synchronization)

Bill Unruh unruh at physics.ubc.ca
Tue Jan 22 04:49:20 UTC 2008

On Mon, 21 Jan 2008, Danny Mayer wrote:

> Unruh wrote:
>>  All I say is that the experiments I have carried out show that ntp is slow
>>  to converge if it starts of badly, and leaves the offset scatter larger
>>  than chrony does. It does have a smaller scatter in the rate. 
> But you are using an extremely old version of ntp and things have radically 
> changed since that version was released. Try rerunning you experiments with 
> ntp 4.2.4 and see what you get then. You also need to fix your calculations 
> if you are going to get good results as I mentioned in a previous message.

I did. The calculations I presented were with 4.2.4, except for the
convergence on initial transient. I have not retried that experiment ( It
takes too long) Most of the results regarding the scattering of the offset
are for 4.2.4. It is a factor of a little over two worse than chrony in
regulating the offset.

In a few weeks I will probably try the initial transient stuff again.
(I am out of town next week)

However, do you believe that the bechaviour  of 4.2.4 under intial conditions is
better than 4.2.0 (eg either no drift file or a bad drift file)?

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