Charles Swiger <cswi...@mac.com> wrote: >> However, what I observe is that the plots of the offset show the derivative >> of the environment temperature, which unfortunately cannot be controlled >> any better. I am considering to locate the crystal that is responsible >> for the timing and see if it could be ovenized or replaced by a more >> temperature-stable oscillator. However, one can argue that it could be >> fixed in software as well. ntpd could sense a changing drift and extrapolate >> it, if necessary helped by input from a temperature sensor. > > You're describing a TCXO; using a temperature sensor to compensate for thermal > drift would gain perhaps a factor of 5 accuracy.
A TCXO could be better than what is fixed as standard (these are HP Proliant and Dell servers), but note that when talking about microsecond accuracy it will be quite difficult to get a freerunning oscillator that does not gain a few microseconds per 5 minutes or so. So there will always be a need for compensation. (I would add a graph showing the offset when it would be possible on usenet) _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
