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    SubjectRe: Time precision, adjtime(x) vs. gettimeofday

    > Well, it it affects gettimeofday which has a precision of 1 part in
    > 10000 (100 ppm), it means that our boot time timebase calibration was
    > not very good to start with, on my set of running VME machines I have
    > the following (values in ppm):
    > ../..

    Boot time calibration can't be perfect... I depends very much on the
    quality of what your are calibrating against, and the bus path to it.

    On most pmacs, I'm calibrating either against a VIA timer which isn't
    _that_ good or on OF value (which are themselves calibrated, I think,
    against the KeyLargo timer).

    On all cases, those will drift some way from what the NTP server will
    give, either a lot or not, it will. So we may end up adjusting our
    kernel rate and thus opening a window for the problem.


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