[ntp:questions] PSYCHO PC clock is advancing at 2 HR per second

David J Taylor david-taylor at blueyonder.co.uk.invalid
Tue Mar 20 15:55:06 UTC 2012

> David Taylor is right that it is normal for Windows to keep running
> the clock at whatever rate was last set after the program setting the
> rate goes away.  It's also true that Windows does not have any rate
> limits itself -- you can easily tell Windows to advance the clock 1
> usec per tick (nominally 15.625 msec), one hour per tick.  Unless I
> misread the nt_clockstuff.c code, it shouldn't be possible to get ntpd
> to set the Windows clock rate more than 500 PPM from nominal.
> Thanks,
> Dave Hart


How does NTPD_TICKADJ_PPM affect this?  If that was set to -800, for 
example, wouldn't the adjustment range be -300/-1300 rather than +/-500? 
Or are you including NTPD_TICKADJ_PPM in "nominal".


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