Windows Timing performance
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Hi, I've written a program to test the performances of a windows timer under different work loads. In a first step we used the program under a windows 98 platform with a timer frequency of 5Hz. So every 200msec the Wintimer should sent a WM-TIME message to the OnTimer function. Because the timer tick frequency of a windows 98 platform is about 18Hz(55msec) there will be approximately a time delay of 20msec. When I start the program with no work load(0 floating point operations) the time delay is also 20 msec, so everything is normal. But when I want to increase the work load to 1.000.000 floating point operations the time delay becomes smaller. I would expect that it would increase with increasing work load! Can anyone explain this? Kind regards, Geert
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Hi, I've written a program to test the performances of a windows timer under different work loads. In a first step we used the program under a windows 98 platform with a timer frequency of 5Hz. So every 200msec the Wintimer should sent a WM-TIME message to the OnTimer function. Because the timer tick frequency of a windows 98 platform is about 18Hz(55msec) there will be approximately a time delay of 20msec. When I start the program with no work load(0 floating point operations) the time delay is also 20 msec, so everything is normal. But when I want to increase the work load to 1.000.000 floating point operations the time delay becomes smaller. I would expect that it would increase with increasing work load! Can anyone explain this? Kind regards, Geert
My semi-educated guess: that your program is getting more scheduled time and can therefore respond quicker to the WM_TIMER message. My guess is that if there was another program consuming more CPU than yours, you might take longer to respond. Joel Lucsy (jjlucsy@concentric.net)