[ntp:questions] micro-optimization

Augustine evandro at mailinator.com
Wed Mar 11 02:01:49 UTC 2009

On Mar 10, 11:13 am, Dave Hart <daveh... at gmail.com> wrote:
> 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.

Just keep in mind that Windows' power management will change the
frequency of a processor, thereby making the count returned by RDTSC
have a variable rate on some processors (namely Intel's Pentium4 and
AMD's Athlon and Opteron).


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