Unruh wrote: [] > Mill's assumptions about the behaviour of clocks is almost certainly > wrong. > Not least because computer clocks are in a highly variable thermal > environment. This means that the drift rate varies with time of day > and day > of week and is NOT 1/f or any other time invariant spectrum. Tests > have > been run where the temperature is measured and an additional > correction due > to temperature is factored into the ntp algorithm, and vastly improved > results are obtained. Chrony gets better results, primarily I believe > because its use results in a varying Allan intercept, and the clock > rate adjustment benefits from that in the noisy thermal environment > of computers > which are used for things other than timekeeping.
I don't run chrony and it has nothing to do with my question. >> The book is on my Amazon wanted list, but I'm not sure how much I >> will appreciate if it's mainly maths. One of my criteria for >> judging image processing papers was "does it contain images?"! > > And a book on time should contain sounds of a clock ticking? What do /you/ think? Was there a smiley missing? > Mathematical analysis is crucial to proper operation of the system. > But it does have lots of graphs if that helps. As I indicated, I find a visual representation very helpful, and I was for ever trying to get people who were applying for expensive but obscure pieces of capital equipment to include some graphs showing the benefits of buying such. David _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
