[ntp:questions] Meinberg NTP monitor, silly question

unruh unruh at wormhole.physics.ubc.ca
Tue Dec 22 20:45:51 UTC 2009


On 2009-12-22, Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
> unruh wrote:
>> On 2009-12-22, Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
>>> David J Taylor wrote:
>>>> "Richard B. Gilbert" <> wrote in message 
>>>> news:ZJydnVuvufm1Wa3WnZ2dnUVZ_h2dnZ2d at giganews.com...
>>>> []
>>>>>> You will find that for the best performance, the NTP PC needs to be 
>>>>>> left running, as initial settling is not quick.
>>>>>>
>>>>> "Not quick" is an extreme understatement!  It takes about 30 minutes 
>>>>> to get a "reasonable approximation".  It can take ten to twelve hours 
>>>>> to stabilize with the best possible approximation of the time.  Once 
>>>>> there it's good for as long as you can keep the power on and the 
>>>>> temperature reasonably stable.
>>>> Richard,
>>>>
>>>> On one LAN-synced system it took bout 90 minutes to get to within its 
>>>> normal offset range, and about the same on a Windows-XP system with a 
>>>> GPS reference clock.  On the Windows-7 system, with a GPS ref-clock, it 
>>>> took about 5 hours.
>>>>
>>>> I do wish there were some way of speeding this up - a variable loop 
>>>> bandwidth or something like that.
>>>>
>>> Lots of luck.  My understanding is that it can't be done without loss of 
>>> accuracy and/or stability.
>> 
>> Nonsense. chrony does it, without loss of accuracy (chrony is about 3
>> times as accurate as ntp is) or stability. It will correct a few hundred
>> second initial error in far less time than ntp takes for a .01 sec error,
>> and without stepping. 
>> 
>
> Then why don't you use chrony and stop bugging us?  If it can replace 

I do use chrony. Until recently I used ntp for refclock support. I am
not bugging you, just pointing out that the claims made here are
nonesense, by conterexample. I had hoped that ntpd would impliment the
chrony clock discipline algorithm, but it is clear that will not happen.
But this is a newgroup to discuss ntp, not the reference implimentation
of ntpd, and chrony is a program that impliments ntp.


> NTPD under most common scenarios for normal and emergency operation and 
> do a better job, I'm sure that it will eventually replace NTPD.  Does 
> anyone see that happening yet?




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