[ntp:questions] Meinberg NTP monitor, silly question
unruh
unruh at wormhole.physics.ubc.ca
Tue Dec 22 18:34:46 UTC 2009
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.
>
> I keep my system running 24x7 except when we have a power outrage
> lasting longer than the run time of the UPS.
>
> If your power is insufficiently reliable, consider a UPS and a gasoline
> (or natural gas) powered generator. If it's important enough to spend
> money on, you can make it almost bullet proof!
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