[ntp:questions] Allan deviation survey

Miroslav Lichvar mlichvar at redhat.com
Tue Sep 14 13:47:38 UTC 2010


On Tue, Sep 14, 2010 at 02:45:01AM +0000, David L. Mills wrote:
> Don't get fooled by the MINSTEP. Precision is defined by the time to
> read the system clock at the user interface and I have never seen
> anything less than 500 ns for that, more typically 1000 ns.

This is what ntpd prints here (patched to use smaller MINSTEP):
ntpd[9357]: proto: precision = 0.086 usec

I've seen values as low as 40 ns. The system has to use TSC as
clocksource though.

-- 
Miroslav Lichvar



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