On 2015-02-24, Paul <[email protected]> wrote:
> On Tue, Feb 24, 2015 at 1:14 PM, Charles Swiger <[email protected]> wrote:
>
>> On Feb 23, 2015, at 11:57 PM, David Woolley <[email protected]>
>> wrote:
>> > On 23/02/15 21:23, William Unruh wrote:
>> >> manual corrections are probably good to 1 sec.
>> >
>> > It's a long time since I did this, but 200ms is more like it
>>
>> However, if you time things with a rhythm you can get to ~50 ms or better
>>
>
> While these performance anecdotes are interesting they (starting with
> unruh@invalid) are all anecdotes. I didn't mention research and real
> numbers by accident.
>
> The underlying assertion is that the chrony method offers some value and is
> superior to NTPd. So I'd like something more than hand-waving regarding
It is superior in that you can do it easily. Whether that is of any
importance to you is of course up to you. Myself I have never used it.
> the performance and if it's better than just setting the clock once and a
> while I'll write something to create a drift file based on the operator
> listening to USNO ticks (or Emerald Time if you have it) and pressing
> return at the right time.
Fine. It has already been written for chrony. For those that want it,
this is an advantage for chrony. I could argue that ntpd is
no better than nothing because I could write a program to do what ntpd
does. While (possibly) true, it is a silly argument.
>
> Someone else can do a version that uses a microphone to listen to the ticks
> -- a stone-age ACTS driver.
>
> With regard to return on investment and underlying arguments about
> "advantages". I don't buy the "Well someone may want to do this so it's
> worthwhile" argument. Doing something foolish or stupid doesn't make
> Chrony better than NTPd.
It is not either foolish or stupid. It was written because Curnoe had a
bunch of computers that spent a lot of time disconnected from the net.
He had a need. Others may or may not. But if you do, then chrony's
having it is an advantage. If you have no need it is not an advantage to
you, but there are lots of things in most programs that I never have a
need for, but their being there is still an advantage of those programs
(assuming the presense does not mess other things up).
>
> Or to put it another way -- NTPd is about precise time transfer and it
> protects you from falsetickers like your wristwatch.
Your wristwatch may well be a much better ticker than the localclock is
(seconds per year rather than hours per year.)
And listening to the time signal on the radio ("At the beginning of the
long dash it is exactly 12:00" for those that live, or lived in
Canada) is much better than seconds per year.
_______________________________________________
questions mailing list
[email protected]
http://lists.ntp.org/listinfo/questions
