Dhrystone
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Dhrystone is a benchmark invented in 1984 by Reinhold P. Weicker. The Dhrystone benchmark contains no floating point operations, thus the name is a pun on the then-popular Whetstone benchmark for floating point operations. The output from the benchmark is the number of Dhrystones per second (the number of iterations of the main code loop per second).
One common representation of the Dhrystone benchmark is the DMIP - Dhrystone MIPS - obtained when the Dhrystone score is divided by 1,757 (the number of Dhrystones per second obtained on the VAX 11/780, a 1 MIPS machine).
The Dhrystone benchmark contains mainly integer and string operations. For a period of time in the 1980's the benchmark was used to compare the optimized code emitted by compilers. Optimizations to the standard libraries and code emitted for string operations were found to greatly increase benchmark numbers. Compiler vendors were motivated to improve their standard libraries, and optimize common string operations (all Intel x86 compatible processors have special instructions for string handling). To this extent the benchmark proved beneficial to all mainstream compilers.
Like most synthetic benchmarks, the Dhrystone benchmark is not particularly useful in measuring the performance of real-world computer systems and has fallen into disuse, replaced by benchmarks that more closely resemble typical actual usage.
References
- Newsgroup posting for calculation of DMIPS (http://groups.google.com/groups?q=DMIPS&hl=en&group=comp.benchmarks&rnum=1&selm=tsengDKq856.Gy6%40netcom.com)
- Reinhold P. Weicker, CACM Vol 27, No 10, 10/84 (http://portal.acm.org/citation.cfm?id=358283)de:Dhrystone