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

brian.utterback at gmail.com brian.utterback at gmail.com
Sun Jan 27 17:03:21 UTC 2008

On Jan 25, 12:53 pm, Unruh <unruh-s... at physics.ubc.ca> wrote:
> The Allan intercept is predicated on a very specific model of the noise in
> a clock ( as I recall basically random gaussian noise at high frequencies,
> and 1/f noise at low). It is not at all clear that real computers comply
> with that.

Then you should read Dr. Mills papers. You are correct that it is not
the case that they comply, but Dr. Mills has demonstrated it
experimentally many
times for many different setups. Additionally, the behavior model is
nto actually
the same over all possible configurations, which lead to his
abandoning the FLL
in the kernel code, since while theoretically useful it added needless
over the observed real world ranges.

Pleasem Dave is not always right about everything, and can be
convinced with data
when he is wrong. But it is very hard to convince him with A Priori
reasoning, since
he has been doing that same reasoning for a lot longer than the rest
of us, and has
tested all his hypotheses on real systems.

Brian Utterback

More information about the questions mailing list