[ntp:questions] Red Hat vote for chrony

Terje Mathisen terje.mathisen at tmsw.no
Tue Dec 9 10:41:28 UTC 2014


William Unruh wrote:
> On 2014-12-09, Charles Swiger <cswiger at mac.com> wrote:
> ...
>> [ ... ]
>>> Of course, in an ideal system designed for clock stability, the clock
>>> variation with temperature would be measured, and an offset based on
>>> the temperature of the crystal applied directly to the output of the
>>> clock itself, before it was supplied to the operating system.
>>
>> Yes; you're describing calibrating a temperature-compensated XO, or TCXO.
>
> There are also versions of ntp which have a temp
> compensation/measurement system compiled in to apply to the clocks. It
> does tend to give much better control of the clock than regular ntpd
> apparently.
>
It does help:

On motherboards with a temperature sensor close to the master crystal, 
you can get somewhere in the 2-10x range improvement in the size of 
temperature excursions.

The correct solution is of course to not depend on $0.10 crystals as the 
time base for dedicated NTP servers. :-)

Terje

-- 
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"



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