"David L. Mills" <[EMAIL PROTECTED]> writes: >Unruh,
>The basic clock discipline feedback loop has been unchanged since 1992, >although minor changes have been made to improve behavior in very long >poll intervals. The only radical change has been using a preliminary >15-minute initial frequency computation when no frequency file is >available. So, if you are comparing ntpd and chrony at initial startup >and without a frequency file, expect to find wide differences in >behavior. Starting ntpd with an intentially "bad" frequency file is not >useful unless you can configure chrony in the same way. Of course I can. And have done so. As you say, the transient response of ntp is terrible-- 3000 sec is far too slow. >If you really do want a definitive experiment, do what I suggested >earlier: measure the transient response of both ntpd and chrony starting >from the SAME initial conditions and with a frequency file containing >zero PPM. Pay attention to the poll interval, whch should be the same in >both cases. That will tell you the story, the whole story and nothing >but the truth. Precisely what I have been doing. >Dave >Unruh wrote: >> [EMAIL PROTECTED] (Danny Mayer) writes: >> >> >>>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. >> >> >> Most of the standard deviation results are with 4.2.4. Only the startup was >> with 4.2.0. Are you saying that "things have radically changed" in the >> handling of the startup? After I collect more data on steady state, I will >> rerun startups both with no drift file and a bad drift file to see how fast >> the convergence is with 4.2.4. >> >> >> _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
