On Feb 10, 2:39 UTC, David Lord <sn...@lordynet.org> wrote: > Target was given above as +/- 10ms so just using > "ntpd -q" will get there but here that seems to take > between 5-8 minutes. Then after starting ntpd it's > about another 4 minutes before ntpd is giving out > time. As you say, it takes a few hours to reach > offsets in low us. If an ntp server is configured > with iburst, the startup time can be even faster.
ntpd syncs to my GPS+PPS much more quickly than that. I'm guessing you're using a substantially older version of ntpd than 4.2.6 and probably also using the default minpoll 6 with your refclock drivers? > These are from a restart yesterday morning: > > 09:54:40 clock PPS(0) 'clk_noreply' # ntpd started > 09:58:57 synchronized to GPS_NMEA(0), stratum 0 > 10:00:18 synchronized to PPS(0), stratum 0 This is not directly comparable because it's from a warm restart of ntpd where no step was needed, but in under 20 seconds it was humming: 10 Feb 05:05:40 ntpd[5988]: 0.0.0.0 c016 06 restart 10 Feb 05:05:40 ntpd[5988]: GPS_NMEA(1) 8024 84 reachable 10 Feb 05:05:40 ntpd[5988]: GPS_NMEA(1) 963a 8a sys_peer 10 Feb 05:05:40 ntpd[5988]: 0.0.0.0 c415 05 clock_sync 10 Feb 05:05:41 ntpd[5988]: PPS(1) 802b 8b clock_event clk_no_reply 10 Feb 05:05:57 ntpd[5988]: PPS(1) 8034 84 reachable 10 Feb 05:05:57 ntpd[5988]: PPS(1) 974a 8a sys_peer The 16s vs. 64s poll intervals only explains part of the difference. Another part is newer ntpd jumps on a working PPS signal as soon as it is reachable, rather than after 4 polling intervals. Cheers, Dave Hart _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
