[ntp:questions] best gps receiver for time synchronization
unruh-spam at physics.ubc.ca
Wed May 13 20:19:04 UTC 2009
"David J Taylor" <david-taylor at blueyonder.not-this-part.nor-this.co.uk.invalid> writes:
>> Since the same machine can run Linux or BSD whose resolution is usec
>> nsec, yes, the hardware can do better. The question is how good is the
>> software in the kernel. If I do a timestamp on an event, how accurate
>> that timestamp?
>> Is it msec? Is it 15msec?
>The precision with which a standard Windows system call returns the
>current time will be 1 millisecond. The value reported by that call may
>step in 1, 10 or 15ms steps depending on the version of Windows you use,
>and whether you turn on the "fast" timer (the multi-media timer).
>I am running ntp on windows and it is reporting offsets of a fraction of a
>millisecond, so does that mean that the milliseconds reported are within a
>millisecond of UTC?
Thanks. That was waht I wanted to know.
>It's not a matter of "how good" is the kernel, it's what the design
>specifications are, if I understand it correctly, and the design specs for
>different versions of Windows are different.
Well, I call "good" to include the design. If a car is designed so that
the wheels fall off every 100 miles, no matter how closely the car meets
the design, it is a bad car.
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