On Fri, Sep 10, 2010 at 10:10:08PM +0000, David L. Mills wrote: > A previous message implied that, once the Allan characteristic was > determined, it would show chrony to be better than ntpd. Be advised > the default time constant (at 64 s poll interval) was specifically > chosen to match trace 1 on the graph mentioned above.
Wasn't that rather for 16s poll interval? From simulations is seems that the phase noise would have to be 10-30 times higher (or the frequency noise lower, but that's unrealistic) to ntpd perform well at 64s poll interval. > In other > words, it is in fact optimum for that characteristic and chrony can > do no better. Well, it does better. With phase noise and random-walk frequency corresponding to the trace 1 from your graph chrony is about 5 times better than ntpd. With 30 times higher phase noise the difference is only in order of tens of percent, but it's still better. -- Miroslav Lichvar _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
