Re: determine cycle counter frequency in user space

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From
Terry Lambert <tlambert2@mindspring.com>
Date
1 May 2001 02:07:57
Subject
Re: determine cycle counter frequency in user space
Message-ID
3AEE7CF7.69D87D5F@mindspring.com

References to

[ Hide this part ]
Mike Smith wrote:
> Use time_second for coarse timing requirements.

[ ... ]

> The cycle counter can't be relied on. Get this through your
> thick head. The clock frequency on many Alpha systems is
> unstable, and on most PCs, it can change out from under you
> with no warning.

[ ... ]

> Hardware sucks; what can I say? You can't do this usefully
> in userspace; stop trying and go buy some real timing hardware
> if you actually care.

Sorry; I didn't get this message in time.

Unfortunately, my code is now working with ~90uS accuracy,
+/- 90uS.

I'll try to be more dilligent in keeping up with my email
from now on... ;-).

-- Terry

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