Dhrystone MIPS (DMIPS)

The Dhrystone test is a benchmark for the computing performance ofcentral processing units( CPU) and of application programs. It was developed in the 1980s, later translated into the Adaprogramming language and is now used exclusively in the "C" programming language as an industrial standard.

The Dhrystone code consists essentially of simple integer arithmetic, string operations, logical decisions and memory accesses, covering most general-purpose computer applications. The test result determines the average time it takes a processor to complete many iterations of a single loop. The Dhrystone performance is specified in DMIPS or Dhrystone MIPS/ MHz.

In the Dhrystone benchmark, the tested computer is compared with a reference machine. The reference computer used was the VAX 11/780 from Digital Equipment, which was popular in the 1980s and was assigned 1 million instructions per second (MIPS) as a reference. The VAX 11/780 achieved 1757 Dhrystone per second. This means that all test results in "Dhrystone per second" must be divided by 1757 to obtain a reference value in MIPS. So a computer with 120 MIPS (120 Dhrystone VAX MIPS) means that this computer works 120 times faster than the VAX 11/780.

A comparison between Dhrystone MIPS (DMIPS) and MIPS (Million Instructions Per Second) is not possible, since the term MIPS refers to the number of instructions in a unit of time, whereas the Dhrystone MIPS are determined for a specific program.

With the benchmarks of the Standard Performance Evaluation Corporation( SPEC) and the Embedded Microprocessor Benchmark Consortium( EEMBC), there are more meaningful benchmarks for processors, computers, programs and embedded systems.