Pete Stephenson wrote: > On Wed, Feb 24, 2016 at 3:22 PM, Neil Green <[email protected]> wrote: >> I currently operate a stratum 1 NTP server in the NTP pool using a U-Blox >> Max-7Q GPS module with PPS attached to, variously, a Raspberry Pi via GPIO >> or a Celeron mini PC via serial DB-9. The machine does nothing but serve >> time to the pool. Operating systems of choice are Debian or FreeBSD. >> >> >> What would be my next step up be, hardware-wise, in terms of improving >> precision, stability, etc? A GPSDO? Budget is limited as far as these things >> go - about £150 UK/$210 US. > > For what purpose? > > In my experience, NTP is able to sync other systems to within 10-100 > microseconds of an NTP server on a LAN. The vagaries of the internet > mean that it's unlikely for NTP clients to sync any closer than a few > tens of milliseconds.
It can be better, but that's not guaranteed. I'm located in Germany and have a setup measuring the offset of some NTP servers in the U.S. against a built-in GPS card, and the offset is below 2 ms most of the time. Martin _______________________________________________ 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.
