[ntp:questions] help with setting up NTP on windows with a USB GPS

David J Taylor david-taylor at blueyonder.not-this-bit.nor-this-part.co.uk.invalid
Sun Dec 6 19:48:34 UTC 2009

"David Woolley" <david at ex.djwhome.demon.invalid> wrote in message 
news:hfgvt5$g6f$1 at news.eternal-september.org...
> David J Taylor wrote:
>> Stated requirement:
>>  - around 1 millisecond (on Window 2000 or XP IIRC).
>> Observed performance examples:
> These don't tell you the jitter due to the scheduling of the application 
> program and interrupt latencies from the real world events to the point 
> where the code tries to read the time.

Of course the application has to be well-designed and use appropriate 
interactions with the OS - that goes without saying.  NTP can measure 
better than a millisecond on Windows.  As the application is an existing 
Windows one, the OS is fixed, and the challenge is then to provide the 
best timekeeping within the imposed constraints.


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