Yes, it looks good, and thanks for clarifying the "before" was using
the user-mode PPS hack in the Windows port of ntpd.
However, it doesn't seem to be working anything like as well as
nominally
the same software installed in 32-bit Windows on PC Stamsund. Compare
the
offsets of 32-bit PC Stamsund (well under 50 microseconds) with 64-bit
PC
Alta (well over 500 microseconds and somewhat periodic).
[]
My guess: the key difference is the one you already identified,
Stamsund is using a precision around -20 (microseconds) while Alta is
stuck with precision -10 and the resulting minimum 0.977 ms jitter.
If you manage to get Alta's system clock to tick 64 times per seconds
instead of 500, 1000, or 2000 times per second, the interpolation code
can correctly correlate the high-resolution counter and system clock
given the 1000 Hz scheduler resolution. Things to try would include
remove -M from ntpd options, prevent Flash or Java or media player
apps from being run.
Cheers,
Dave Hart
Dave,
Looking in even more detail, I found that....
PC Stamsund had set, from 2009 Aug 23:
NTPD_USE_INTERP_DANGEROUS=1
PC Alta had set, from 2010 Dec 19:
NTPD_USE_SYSTEM_CLOCK=Yes
I should have seen that before! Removing the system_clock and adding the
interp_dangerous from Alta has resulted in an immediate improvement.
Thanks for encouraging me to look further!
Case solved (I hope) and 64-bit PPS working on Windows-7. My thanks for
your work on this.
Cheers,
David
--
SatSignal software - quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk
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