On Sat, Mar 31, 2012 at 18:12, A C <agcarver+...@acarver.net> wrote: > I understand that the jitter will change but I'm talking about the minimum > possible jitter that ntpd can report for a given system. Using 4.2.6, the > minimum possible jitter reported (such as what is shown in the ntpq > billboard when ntpd first starts up) was 0.061 on my NetBSD system. > However, with 4.2.7p259 (and some of the earlier versions as well) the > minimum possible jitter exactly doubled to 0.122 on the same system. > > It would appear that the method used to compute the minimum possible jitter > changed between the two versions.
That value is stored as a power of 2, explaining the exact doubling. The method did change to separately determine the minimum apparent time to read the clock (even when the clock reading does not change every time) from the minimum change between readings. There is extra code in the clock reading path to ensure readings never go backward without notice, as well. Cheers, Dave Hart _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
