[ntp:questions] Loop Frequency and Offset

David Woolley david at ex.djwhome.demon.invalid
Sun Sep 25 19:55:42 UTC 2011

Miguel Gonçalves wrote:
> I have a machine running FreeBSD 7.4 and it seems that the CPU clock runs
> too fast or slow (positive offset in loopstats is fast or slow?).

Neither.  A constant sign on an offset is an indication that something 
is broken, either the algorithm, or the static frquency error exceeds 
500ppm.  Offsets should be normally distributed around 0.  Well, maybe 
not a normal distribution, but certainly they should be both sides of zero.

> The frequency is too high it seems. Since this is a software clock can this
> be changed to get a lower frequency and thus a smaller offset?

tickadj can be used to make 100ppm steps, but if the clock is out by 
more then 500ppm, something is broken, and it would be better to fix it.

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