[ntp:questions] Best solution for millisecond accuracy

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Sat Mar 24 21:54:58 UTC 2007

>However, for a high percentile of system times being within 1ms of the
>reference, he probably should be using PPS timing with equal length 
>cables between the timing source and all the machines.

Don't worry about the cable length until you get down to the microseconds.

The speed of light is 1 ft per nanosecond.  That's in vacuum.  It's slower
in cable.  1/2 or 3/4 is a good guess.

So 50 ft of cable is 100 ns or 1/10 of a microsecond or
1/10000 of a millisecond.

These are my opinions, not necessarily my employer's.  I hate spam.

More information about the questions mailing list