[ntp:questions] micro-optimization

Dave Hart davehart at gmail.com
Tue Mar 10 16:13:07 UTC 2009

I have released a new test version of 4.2.4p6 with numerous Windows-
specific improvements compared to the baseline 4.2.4p6.  Since my last
release, the most significant change is to read the processor cycle
counter using the RDTSC instruction directly when it is equivalent to
QueryPerformanceCounter.  When it is not equivalent, ntpd is allowed
to roam freely across all logical processors once again.

I've also made small changes to the counter frequency tuning code to
balance observation time (longer is better quality, to a point, but
also means it takes longer to effect the counter frequency
compensation after startup).  The counter frequency tuning messages
have been further quieted to once every 8 hours after the initial
compensation is done.


has binaries, debug binaries, symbols, and source, most people will


Dave Hart

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