Difference to Classic: precision value

[Gary E. Miller]

Yo Achim!

On Sun, 26 Mar 2017 12:50:53 +0200
Achim Gratz <Stromeko at nexgo.de> wrote:

> While playing around with the two new NTP boxen, I noticed a differnce
> to classic: the precision value reported by NTP classic for both is
> -22, while NTPsec reports -20 (run 'ntps -c rv').  At least for the
> rasPi the NTPsec value looks to be correct (since the time base is a
> nominally 1MHz software defined counter).  But I still wonder where
> the difference comes from.

I remember fixing it.  But after looking at the git log I'm not finding
where/when.  It was one of several places where it was assumed precision
could never be better than -20 ( about 1 micro second).

The different refclocks each do their own precision calculations, which
driver are you talking about?  

The PPS refclock got 'fixed' in commmit
046cc1288def138dbc05477211785b57f7d4d29e.

The gpsd refclock got 'fixed' in commit
3d0ff052977402dfacabc37d47568ddd1ce0d47e

Precision is not used much by ntpd, it is just passed along.  Each
driver just pulls out a WAG for it, so do not take it very seriously.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
	gem at rellim.com  Tel:+1 541 382 8588

	    Veritas liberabit vos. -- Quid est veritas?
    "If you can’t measure it, you can’t improve it." - Lord Kelvin
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