[time] Best attainable offset of ntpd?

Rob Janssen pe1chl
Fri Jun 23 09:11:34 UTC 2006


Philip M. White wrote:
> All,
>
> What is the best offset that you have been able to attain with ntpd?
> With a Garmin 18 LVC + LinuxPPS + Linux 2.6.17 + ntpd 4.20, the best I
> can get is an offset of about 0.006 ms.  This offset is never steady --
> it drifts from positive to negative.  Right *now*, for example, it is
> -0.017 ms.  I use this machine for real work and play (X, multimedia,
> OpenOffice, etc.).
>   
This is typical for such a machine.  Remember this is of the order of 
microseconds.
I get the same performance from a standard kernel and user-process PPS 
handling.
(using gpsd)
It is several orders of magnitude better than you would get with only 
message
handling (no PPS) or sync from the network.

Rob


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