How to Calculate MIPS Rating

In the field of computers, MIPS (Millions of Instructions Per Seconds) is a unit used as a benchmark for CPU (Central Processing Unit) performance. The MIPS rating of a CPU refers to the number of low level machine code instructions a processor can execute in one second. Calculating a MIPS rating is not difficult, but it has very limited value as a benchmark given the complexity of the factors besides processor speed determining performance in today's computers. Today's processors have very different designs and architectures, and some get much more "work" done per instruction than others, so it is not at all unusual for a computer with a 20 MIPS CPU to actually run many apps slower than a computer with a 5 MIPS CPU due to the chip design and/or other non-CPU factors, such as bus speed.

Instructions

1. Calculate a MIPS rating using this basic formula:

   MIPS = n / (t x 1,000,000) where n is the number of instructions executed and t is the time it took to execute those instructions in seconds.

2. Calculate MIPS using this example: n = 10 million; t = .2

   10,000,000 / .2 x 1,000,000 = 10,000,000 / 200,000 = 50; that is, a MIPS rating of 50.

3. Compare the MIPS rating you calculated with the one provided in the specifications section of the manufacturer's website for your computer's CPU and see if you calculated correctly.

Tips & Warnings

• The MIPS rating for the CPU of many computers can be found in the detailed specifications in the online help section of the manufacturer's website.

References

• "Measuring Computer Performance: A Practitioner's Guide;" David Lilja; 2000
• Vintage Computers: MIPS/MFLOPS