Hal, Hal Murray wrote: > How fast does Windows normally slew? I was expecting it to be 500 > ppm which would take a long time to slew a whole second.
Maybe the following is a bit nitpicking, but "Windows" doesn't slew the time at all. Whichever time adjustment service is running, it can modify the tick adjustment value under Windows as required/desired. 500 ppm is a limitation which is specific to ntpd, and maybe operating systems which implement the kernel clock algorithm developed by Dave Mills, which is great, BTW. AFAIK the limitation is with respect to the time synchronization algorithm and the stability of the control loops. Windows doesn't implement Dave Mills' clock model, and other time adjustment services are not limited to the 500 ppm value. The article I was referring to can also be found in the NTP questions mailing list archive: http://lists.ntp.isc.org/pipermail/questions/2005-October/007296.html In the log output you can see that the tick adjustment value is temporarily changed from 156250 to 78125, so the system time temporarily increases with half speed only until the time offset introduced by the leap second has been compensated. Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
