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Dhrystone howto

1,464 bytes added, 02:45, 15 December 2010
Dhrystone Fundamentals
independent certification means that customers are dependent on processor vendors to
quote accurate and meaningful Dhrystone data.
 
== What Dhrystone really does ==
<font style="font-size:90%">From Clarify.doc (Included in Dhrystone 2.1), Rick Richardson</font><br />
 
<ul>
<li> DHRYSTONE is a measure of processor+compiler efficiency in
executing a 'typical' program. The 'typical' program was
designed by measuring statistics on a great number of
'real' programs. The 'typical' program was then written
by Reinhold P. Weicker using these statistics. The
program is balanced according to statement type, as well
as data type.</li>
 
<li>DHRYSTONE does not use floating point. Typical programs don't.</li>
 
<li>DHRYSTONE does not do I/O. Typical programs do, but then
we'd have a whole can of worms opened up.</li>
 
<li>DHRYSTONE does not contain much code that can be optimized
by vector processors. That is why a CRAY doesn't look real
fast, they weren't built to do this sort of computing.</li>
 
<li>DHRYSTONE does not measure OS performance, as it avoids
calling the O.S. The O.S. is indicated in the results only
to help in identifying the compiler technology.</li>
 
<li>DHRYSTONE is not perfect, but is a hell of a lot better than
the "sieve", or "SI".</li>
 
<li>DHRYSTONE gives results in dhrystones/second. Bigger
numbers are better. As a baseline, the original IBM PC
gives around 300-400 dhrystones/second with a good compiler.
The fastest machines today are approaching 100,000.</li>
</ul>
<font style="font-size:110%"><b>Dhrystone Characteristics</b></font>
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