Re: More accurate Timerevent



On Nov 20, 1:53 am, nowh...@xxxxxxxxxxxxxx wrote:
<snip>
If you need to measure a time-critical algorithm then do not use the
GetTickCount() function.  Instead, use the Win32 API functions
QueryPerformanceCounter() and QueryPerformanceFrequency().
(Windows.pas)
<snip>

I believe there are some cache issues with QPF (which calls RDTSC) when
calculating the calling overhead (call the RDTSC asm three times,
checking the call overhead on the third to second difference).

If you google for RDTSC and/ or Har-gis you may get more information
(Har-gis was a company or name which was used by a poster of details on
using RDTSC & QPF).

Even with a higher resolution you will still have inaccuracies due to
Windows indeterminate system activity.

Alan Lloyd

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