how much is the minimum interval value of the asynchronous timers ?

[ÐÄÒâÎÞÑÄ]

I can find the help information asynchronous timers. Following sentences are
about the minimum interval value of the asynchronous timers.

"The asynchronous timers are implemented using the Windows multimedia timer
functions. Therefore, depending on the model of the machine you are working
on, the minimum interval value that you can use may differ. If this interval
is smaller than the resolution allowed by your system, then unpredictable
results may occur. This behavior typically occurs when you set the interval
below 10ms."

For example,my environment is that CPU intel P4 2.0GHz , Windows XP. I want
to know the minimum interval value of the asynchronous timers and how to set
smaller interval value <= 1m
s.

thanks your suggestions!

[drohacek]

Multimedia timer resolution really is hardware and OS dependent, but certainly any P4 system running XP will have the maximum resolution of 1ms. I have attached a program (source and .exe) that shows how to determine the maximum resolution. It uses the code given in this MSDN topic.

Call SetAsyncTimerAttribute and set the ASYNC_ATTR_INTERVAL attribute to .001 to set the timer interval to 1 millisecond.