Re: [gpsd-dev] RaspbPi HOWTO

[Gary E. Miller]

Yo All!

On Thu, 5 May 2016 10:39:40 -0700
"Gary E. Miller" <address@hidden> wrote:

> The NTP over the 100Base-T that goes in the USB High-Speed to the Pi,
> gets 0.3 milliSec of jitter.
> 
> address@hidden:~# ntpq -p
>      remote           refid      st t when poll reach   delay
> offset  jitter
> ==============================================================================
> +spidey.rellim.c .GPS1.           1 u  685 1024  377    0.282 0.417

Whoops that one was during a compile.  Here is one for quiescent Pi2, really
0.3 milleSec:

address@hidden:/usr/local/src/GPS/gpsd/gpsd# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+spidey.rellim.c .GPS1.           1 u  777 1024  377    0.282    0.417   0.302
*catbert.rellim. .SHM.            1 u  497 1024  377    0.329    1.168   0.707
+darth.inow.com  204.17.205.1     2 u  981 1024  377    0.582    0.723   0.448

It will jump to 0.500 with any load at all.
==============================================================================
+spidey.rellim.c .GPS1.           1 u   78 1024  377    0.260    0.928   0.590

Does ntp have a way to show the jitter bounds for a longer period of time?
Say average ovver an hour or a day?

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

pgpCFIRhUxMKz.pgp
Description: OpenPGP digital signature