On 27 September 2011 01:29, unruh <un...@wormhole.physics.ubc.ca> wrote:
> Any(?) gps receiver which has PPS output does better than 1us. Any > network does much worse than 1 us ( more like 10s of us to hundreds). > I might be wrong but checking for instance the Garmin 18 LVC specifications (http://www8.garmin.com/products/gps18oem/spec.html) I do not see better than 1 us accuracy. > > I know... :-) My cable connection is really bad for NTP... I can't get > > better than 3 us. That is why I have 2 stratum 1 GPS receivers onsite. > > You will NOT bet 3us from any network connection. > Are you sure you are not confusing microseconds (us) with milliseconds > (ms)? > I don't mix ms and us... I wasn't BETTING on anything... :-) It was a typo of course (errare humanum est). > And even with a high accuracy timing receiver you will not get better > than ab out 1us because of hardware interrupt latencies and variability, > etc (and thermal wandering of your computer clock) unless you have some > very specialised hardware. > 1 us is OK for me. Cheers, Miguel _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
