Yo All! New data for poll=3 (8 Sec).
Xeon:
Local Clock Local Clock Local Clock PPS PPS
Poll Freq Offset 90% Jitter 90% Stability 90% Offset 90% Jitter 90%
1 495ppb 16.9us 27.7ppt 39.0us 26.7us
2 332ppb 20.9us 15.6ppt 40.6us 29.7us
3 165ppb 20.5us 7.5ppt 34.6us 27.9us
6 570ppb 10.2us 1.2ppt 34.2us 16.3us
The above is pretty clear that for every 90% measure the best is for
poll=6, except Frequency Stability. That is OK since the goal is to
optimize for time, not frequency.
I think the frequency shifting is due to ntpd pulling the xtal against
temp changes.
RasPi3:
Local Clock Local Clock Local Clock PPS PPS
Poll Freq Offset 90% Jitter 90% Stability 90% Offset 90% Jitter 90%
1 1.1ppm 0.43us 2.3ppt 1.6us 0.34us
2 1.1ppm 0.08us 2.9ppt 2.2us 0.20us
3 0.5ppm 0.18us 1.9ppt 3.0us 0.56us
6 1.4ppm 3.3us 2.2ppt 68us 9.7us
Here it is a litle less clear if poll=1 or =2 is best. poll=1 has the least
PPS Offset, but for a 30% reduction in offset, the Local Clock Jitter
reduces by over a factor of 5. 3 is getting worse and 6 is just bad.
I'll probably rerun the =1 and =2 numbers eventually, But poll=4 is
running now. More data in a few days.
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
g...@rellim.com Tel:+1 541 382 8588
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