[ntp:questions] Frequency Offset
David J Taylor
david-taylor at blueyonder.co.uk.invalid
Sun Feb 26 08:51:06 UTC 2012
"Richard B. Gilbert" <rgilbert88 at comcast.net> wrote in message
news:X_ednYrcXr9Hz9TSnZ2dnUVZ_rCdnZ2d at giganews.com...
> Get ready for a shock. NTPD needs thirty minutes or more to get a
> reasonable facsimile of the correct time. To get the microseconds
> right, NTPD needs more like ten hours! It's not a very good fit for
> running 9AM to 5PM. You set it running and leave it running 24x7!
I just happened to check a warm NTP restart on a stratum-1 Windows XP
server. The offset was stable within 30 minutes, and the jitter had
settled at a steady level of 2.5 microseconds after about 35 minutes.
On a Windows-7/32 stratum-1 server, the offset reached stability after 7
minutes, and the jitter reached a stable value (20 microseconds) after
less than 30 minutes.
On a Windows-7/64 stratum-1 server, the offset reached stability after 4
minutes, and the jitter reached a stable value (30 microseconds) after
less than 20 minutes.
Both Win-7 servers have NTPD_USE_INTERP_DANGEROUS=1 set, as it produce
better results sometime in the past.
More information about the questions