Michael Di Domenico wrote: > I've used NTP for years, but i was under the impression that it is not > able to synchonize the clocks below 1 or 2 seconds. Can you point me > towards a specific article that speaks about the configuration > parameters to get ntp sync'd that low?
Hi Michael -- PC hardware and operating systems can put some limits on NTP performance, though with some attention to detail getting ~1 microsecond with an attached hardware reference clock is fairly straightforward. On a lightly loaded LAN, machines can be sync'd to a server on the same LAN to a few hundred microseconds. Challenges may be (a) in the Windows world, earlier versions (prior to some SP level of XP) have inherent limitations on timekeeping accuracy, and (b) Linux does not directly support high accuracy timekeeping with hardware clocks that provide a PPS signal. For various (mainly political, it seems) reasons you need to do a kernel patch to enable use of the PPS signal. I have a bunch of statistics showing NTP performance at http://www.febo.com/time-freq/ntp/stats/index.html. There, you can see how a group of very high performance stratum 1 servers (with directly connected reference clocks) look across the local LAN, as well as how some local stratum 2 and external stratum 2 servers look. There's also a link there to a page that describes what is probably the most accurate hardware available for an NTP server (and which costs less than $300 to implement). John _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
