> Local clock frequency offset, as opposed to local clock time offset. Most NTP documentation calls that drift. Its magnitude is not very interesting when discussing quality of time. Changes over time can be interesting. It's usually much more interesting to look at the clock offset.
There are two sources for drift. One is crystal error. That part often makes a good thermometer. The other is software. If somebody gets the arithmetic a bit wrong, ntpd can correct just like it does for the initial hardware error. For many years, Linux had a not-good measurement of the system clock frequency at boot time. If you rebooted, you got a different answer. It was close, just not good enough in the low bits if you wanted good timekeeping. Jun 2 10:34:25 fed kernel: tsc: Detected 1596.750 MHz processor Jun 9 11:06:24 fed kernel: tsc: Detected 1596.966 MHz processor Jun 19 11:42:22 fed kernel: tsc: Detected 1596.978 MHz processor -- These are my opinions. I hate spam. _______________________________________________ devel mailing list devel@ntpsec.org http://lists.ntpsec.org/mailman/listinfo/devel
