On Feb 10, 2:24 am, Dennis Lee Bieber <wlfr...@ix.netcom.com> wrote: > On Tue, 9 Feb 2010 21:45:38 +0000 (UTC), Grant Edwards > <inva...@invalid.invalid> declaimed the following in > gmane.comp.python.general: > > > Doesn't work. datetime.datetime.now has granularity of > > 15-16ms. > > > Intervals much less that that often come back with a delta of > > 0. A delay of 20ms produces a delta of either 15-16ms or > > 31-32ms > > WinXP uses an ~15ms time quantum for task switching. Which defines > the step rate of the wall clock output... > > http://www.eggheadcafe.com/software/aspnet/35546579/the-quantum-was-n...http://www.eggheadcafe.com/software/aspnet/32823760/how-do-you-set-ti... > > http://www.lochan.org/2005/keith-cl/useful/win32time.html > -- > Wulfraed Dennis Lee Bieber KD6MOG > wlfr...@ix.netcom.com HTTP://wlfraed.home.netcom.com/
Gabriel Genellina reports that time.clock() uses Windows' QueryPerformanceCounter() API, which has much higher resolution than the task switcher's 15ms. QueryPerformanceCounter's resolution is hardware-dependent; using the Win API, and a little test program, I get this value on my machine: Frequency is 3579545 ticks/sec Resolution is 0.279365114840015 microsecond/tick -- Paul -- http://mail.python.org/mailman/listinfo/python-list
