Re: [chrony-dev] refclock prefer and log

[Håkan Johansson <f96hajo@xxxxxxxxxxx>]

> > I'm testing chrony (current git) with two GPS reference clocks, but am
> > suffering from chrony moving between the two equally good sources as
> > reference clock.
>
> In what sense suffering? Those two clocks should be equivalent to better than
> a microsecond if you are using pps. If not, then it might well depend on the
> length of the sentences being issued.  What are you finding?

Yes, they are giving the same time, within about 1-3 us, often less.  Std 
dev around 0.8-1.5 us.  I guess most jitter comes from the interrupt 
latency (measured once with a scope, is about 20 us, jitter by ~2 ms) 
until gpsd picks the pulse.  I've one gps pps later by 10 ms to not have 
the PPS pulses on top of each other, and the other serial messages are not 
in that window.

Cheers,
Håkan