[ntp:questions] chrony and ntp comparison-- ADSL hookup

Richard B. Gilbert rgilbert88 at comcast.net
Wed Feb 20 21:32:32 UTC 2008


Unruh wrote:
> "David J Taylor" <david-taylor at blueyonder.neither-this-bit.nor-this-bit.co.uk> writes:
> 
> 
>>Unruh wrote:
>>[]
>>
>>>>- the default for min and max poll are 6 and 10 (IIRC), and not 4
>>>>and 7
>>>
>>>
>>>And so? Exactly how is this supposed to make a difference?
>>
> 
>>It means that your tests are not carried out on an "out of the box" 
>>configuration, and therefore perhaps less useful than they might otherwise 
>>be.  It's possible that some servers would see min/maxpoll of 4 and 7 as 
>>abusive.
> 
> 
> And no "out of box" test is possible. Neither ntp ( althoug it is much
> closer) or chrony are set up to do so. 
> Right now I do not care what servers find abusive. I am using my own
> server, so I decide what is abusive. I am not advocating these parameters,
> I am using them to test ntp and chrony. ALL of the tests indicate that
> chrony disciplines the clock about a factor of 2-3 better than does ntp.

Testing ntpd and chrony using a local server or servers is not a very 
realistic test of "real world" performance!

Try configuring both with the same set of four to ten internet servers. 
  Set up a stratum 1 server using GPS or a cesium clock as a reference 
to serve as a standard to measure with.  Collect statistics for a month 
or so.

Then tell us what you learned.




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