Felipe Monteiro de Carvalho wrote:
I once implemented a high precision timer on linux, but I don't
remember how I did it. Look at the code here:
http://wiki.lazarus.freepascal.org/EpikTimer
Thanks, I'll have a look at the code for more details. From the wiki, it
sounds like there might be some issues EpikTimer implementation though.
* .... Timestamp Counter.
* Pentium IV 3,2Mhz on Windows and Linux with great precision (~
3,220,000,000 ticks per second)
Timestamp counter from the CPU (assuming we are speaking of RDTSC) is
susceptible to many issue. eg: A Intel P4 3.2Mhz does not always produce
3,220,000,000 ticks per second. Powersaving features like SpeedStep,
Hibernate etc all affect the CPU clock speed. Also on a multi-core
system, not all cores are guaranteed to run at the same clock speed.
Above information was gathered from the WikiPedia article.
http://en.wikipedia.org/wiki/Rdtsc
Anybody know what Win32's QueryPerformanceCounter() uses internally to
get a stable timer? Or is QueryPerformanceCounter also susceptible to
powersaving features?
Regards,
- Graeme -
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