[ntp:questions] 500ppm - is it too small?

David J Taylor david-taylor at blueyonder.not-this-part.nor-this.co.uk.invalid
Wed Aug 19 10:07:21 UTC 2009


"Harlan Stenn" <stenn at ntp.org> wrote in message 
news:ywn9r5v87mp3.fsf at ntp1.isc.org...
>>>> In article <ywn9ab1xrquz.fsf at ntp1.isc.org>, Harlan Stenn 
>>>> <stenn at ntp.org> writes:
>
>>>> In article <h6dh6d$rgi$1 at walton.maths.tcd.ie>, dwmalone at maths.tcd.ie 
>>>> (David Malone) writes:
> David> Indeed - to push us back on track a little, here's a graph of the
> David> drift values from a few hundred machines:
>
> David> http://www.maths.tcd.ie/~dwmalone/time/drifts.png
>
> Harlan> Again, drift values are about the clock's *time*, and the 500ppm
> Harlan> slew limit is about the clock's *frequency*.
>
> I was, of course, insane when I wrote that.  I misread and thought that
> offsets were being plotted, not drift file values (which are, indeed, 
> the
> ppm frequency offsets).
>
> -- 
> Harlan Stenn <stenn at ntp.org>
> http://ntpforum.isc.org  - be a member!

David's graph changed my view - from "is 500ppm too small?" to "500ppm is 
not an unreasonable value".  My thanks to all who have contributed.

Cheers,
David 




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