[ntp:questions] Can a clock drift be too big for ntpd?

Uwe Klein uwe_klein_habertwedt at t-online.de
Sat Oct 20 18:51:42 UTC 2007


Steve Kostecke wrote:
> On 2007-10-20, Jos van de Ven <jos at notavailable.nl> wrote:
>>so my system clock runs too fast due to 1000 Hz setting as I
>>understand. I read that -148 ppm is not a good clock; should be no
>>more than absolute 50 ppm.
> 
> 
> That's simply not true. 
> 
> ntpd is able to apply a frequency correction of between -500 ppm and
> +500 ppm.
> 
> As long as you are not operating at the margins (i.e. close to +/- 500)
> ntpd will be able to discipline your clock.
> 
Just to give an idea about quality of std commercial xtals
el cheapo as found on MOBOs:

tolerance (25°C):
	±50ppm
stability over operating temp range:
	±50ppm
aging per year:
	±5ppm/a




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