Re: PPS in GPSD vs Chrony

[Miroslav Lichvar]

On Tue, Jun 30, 2020 at 12:49:13AM -0700, Gary E. Miller wrote:
> Yo Miroslav!
> 
> On Tue, 30 Jun 2020 08:31:28 +0200
> Miroslav Lichvar <mlichvar@redhat.com> wrote:
> 
> > For example, I set the PPS on my ublox units to
> > 32 Hz to get more samples and improve the stability.
> 
> Interesting.  Do you have data on this configuration compared to
> plain PPS?

Here is a quick test comparing the PPS rate of 32 and 1 Hz. The
polling interval didn't change (1 second) and it was running on an
idle system (an Orange Pi PC). The RMS offset value is about 4.7 ns vs
13.5 ns, so the improvement is not as good as the square root of the
rate ratio, but still significant.

https://i.imgur.com/9E7zUai.png

-- 
Miroslav Lichvar