On 2014-04-26, Paul <tik-...@bodosom.net> wrote: > On Fri, Apr 25, 2014 at 11:22 PM, William Unruh <un...@invalid.ca> wrote: > >> I have 8 machines that reliably sync from one GPS PPS driven >> machine (all using chrony) and they get time reliability of about >> 10microseconds >> > > > How do you determine the 10 micosec. value?
Two ways. One is to simply use the offset scatter as an estimate of the time performace (It is at least some sort of upper bound, but as I have said, not terribly accurate) and secondly by hooking a GS PPS to the machine and looking at the offsets on that. > > And why are you conflating NTP performance with Chrony performance? BEcause they are comparable ( chrony is somthing like 2-3 times better than ntpd, but not 1000 times better). They both use ntp packet exchange to exchange time. ntpd uses a (slow) very simply feedback loop, chrony uses a linear regression, but again the two are comparable. _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
