in reply to Re: Microseconds in Per
in thread Microseconds in Per

Unfortunately, HiRes doesn't work well on Windows machines, where it doesn't provide granularity better than ~ 30 ms. In fact, I've been continuously dissapointed trying to find good solutions for high resolution timers on Windows. Even calls to native Win32 didn't help - the 30 ms seems to be a magic barrier.

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Re^3: Microseconds in Per
by Tanalis (Curate) on Jun 15, 2005 at 06:59 UTC
    Interesting.

    I've done some quick research into this, and it turns out that while it's possible to obtain a timestamp in Windows to 100-nanosecond accuracy, the value returned is only updated once each timer tick[1], or about once every 16 milliseconds.

    It'd seem that that update mechanism is the "magic barrier" you see. Cambridge University offer a solution to this, written in C++ - but whether that'd help you any I don't know :)

    -- Foxcub
    #include www.liquidfusion.org.uk

    1. http://www.cl.cam.ac.uk/users/kw217/useful/win32time.html

[reply]

      Time::HiRes already has this mechanism built in.

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[reply]
[d/l]
      This is very interesting, thanks. I had the same problem with Windows' native "high frequency counters" and now I understand better why.
[reply]

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