Joseph Gray wrote: >> The fundamental difference between SNTP and NPT is that SNTP does only a >> period check and adjustment, so the clock can drift significantly >> between polls. NTP on the other hand attempts to continuously steer the >> clock, and uses a much more sophisticated algorithm to determine the >> > offset. > >> John >> > > I knew SNTP was not as good as NPT, but I would have thought that SNTP kept > the clock accurate to at least the nearest second. Obviously not. So, what's > the worst that a typical PC clock would be off when using SNTP? >
I've found that when Windows is behaving its SNTP client does a pretty good job of keeping the system time within 100ms of an NTP server. Here's a screenshot of NTPmonitor showing my office PC's time offset overnight: http://flounder.jimking.net/~jim/files/ntpmonitor-boron.png (The red line in the plot is the server that the PC is syncing with.) At times, I have seen Windows timekeeping get squirrely, and in that case I'll see large excursions. Most of the time it behaves pretty well. A hint: For some reason the SNTP client needs/prefers/desires a ",0x1" tacked onto the end of the SNTP server name. e.g. "net time /setsntp:us.pool.ntp.org,0x1". Does anybody know exactly what the ",0x1" does? My FreeBSD box with an M12 keeps much better time, of course. :) Jim _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
