[ntp:questions] NTP vs chrony comparison (Was: oscillations in ntp clock synchronization)
David L. Mills
mills at udel.edu
Mon Jan 28 03:06:47 UTC 2008
It doesn't stop working; it just clamps whatever it gets to +-500 PPM as
appropriate. If the intrinsic error is greater than 500 PPM, the loop
will do what it can with the residual it can't correct showing as a
systematic time ofset.
Danny Mayer wrote:
> David L. Mills wrote:
>>Unless the computer clock intrinsic frequency error is huge, the only
>>time the 500-PPM kicks in is with a 100-ms step transient and poll
>>interval 16 s. The loop still works if it hits the stops; it just can't
>>drive the offset to zero.
> Yes, I found this out when my laptop stopped disciplined the clock and
> was complaining about the frequency limits and I started digging into
> the code to figure out why.
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