RE: Re[4]: [GD-Windows] Performance timing
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RE: Re[4]: [GD-Windows] Performance timing
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From: tweety <mi...@sy...> - 2004-02-11 09:00:04
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Same here; this was what I was talking about. Besides, rdtsc and queryperformancetimer has some very nasty sincronization problems with multiple processors (they give the time slightly different wether the code is run on different processors). Good old GetTickCount does its job :) ---------------------------------- Peace and love, Tweety mi...@sy... - twe...@us... YahooID: tweety_04_01 -----Original Message----- From: gam...@li... [mailto:gam...@li...] On Behalf Of Carl Bevil Sent: February 10, 2004 8:27 PM To: Simon O'Connor Subject: Re[4]: [GD-Windows] Performance timing Did that, and they have a nice utility that performs some timing tests on your machine and spits out a report (it's at http://developer.nvidia.com/object/timer_function_performance.html). The report had interesting results: ----- QueryPerformanceFrequency() freq = 0 2593560000 method 0: QueryPerfCntr..() 10000 times tot: 0 6720740 avg: 672.074000 avg time: 2.59132e-007 method 1: GetTickCount() 10000 times tot: 0 260708 avg: 26.070800 avg time: 1.00521e-008 method 2: TimeGetTime() 10000 times tot: 0 1420712 avg: 142.071200 avg time: 5.47785e-008 method 3: Pentium internal high-freq cntr() 10000 times tot: 0 840856 avg: 84.085600 avg time: 3.24209e-008 ----- I've left out the data for less than 10,000 iterations for sake of length; the averages were similar for these cases (and I ran the test a couple times with similar results). It looks like GetTickCount is the fastest, at least for this test setup on my machine. Am I reading the results wrong? I would have expected RDTSC to be the fastest. What could this mean? Is this because of the cache effects that Jon mentioned? Just curious. :-) Tbanks! Carl ------------------------------------------ Tuesday, February 10, 2004, 4:44:01 PM, you wrote: > Hi Carl, > Have a search around nVidia's developer website > (http://developer.nvidia.com), IIRC they did presentation surveying > each of the major timing methods with regard to using them to profile > code and the advantages and disadvantages plus latencies of each. ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn _______________________________________________ Gamedevlists-windows mailing list Gam...@li... https://lists.sourceforge.net/lists/listinfo/gamedevlists-windows Archives: http://sourceforge.net/mailarchive/forum.php?forum_id=555 |
