[ntp:questions] Performance?

dhavey dhavey at gmail.com
Mon Dec 22 21:52:05 UTC 2008


On Dec 22, 1:25 pm, Unruh <unruh-s... at physics.ubc.ca> wrote:
> It is because you are using the nmea from them, not the PPS input and NMEA
> takes a few msec to go from the GPS to your computer ( 60 characters at
> 9600BD ).
>
> dhavey <dha... at gmail.com> writes:
> >This is the ntpq -p output from 2 machines connected to Garmin GPS's.
> >The machines ip's of the 2 machines are 192.168.0.28 and .29.  They
> >are about a millisecond apart!  That's no better than the server
> >without the GPS.  What did I do to deserve such lousy performance.?
> >server 127.127.20.0 prefer minpoll 4
> >fudge 127.127.20.0 refid GPS flag3 1 flag2 0 time1 0.0
> > and the machines are peered together.
> >     remote           refid      st t when poll reach   delay
> >offset  jitter
> >==============================================================================
> >*192.168.0.2     69.25.96.13      2 u   83 1024  377    0.898
> >-0.201   0.456
> > 192.168.0.26    192.168.0.2      3 u  171 1024  376    1.588
> >-1.921   0.416
> > 192.168.0.27    192.168.0.2      3 u  204 1024  376    1.206
> >2.312   0.008
> > 192.168.0.29    192.168.0.28     4 u  323  256  166    0.110
> >0.908   0.299
> > GPS_NMEA(0)     .GPS.            0 l    -   16    0    0.000
> >0.000   0.001
> >     remote           refid      st t when poll reach   delay
> >offset  jitter
> >==============================================================================
> >+192.168.0.26    192.168.0.2      3 u   67  512  177    0.100
> >-2.753   0.374
> >+192.168.0.27    192.168.0.2      3 u   67  512  377    0.055
> >2.018   0.314
> >*192.168.0.28    192.168.0.2      3 u  120  512  137    0.020
> >-0.953   0.337
> > GPS_NMEA(0)     .GPS.            0 l    -   16    0    0.000
> >0.000   0.001


According to ./ppstest the GPS works until I start ntpd.




More information about the questions mailing list