How to compare speed of MCU or MPU

If we want to compare processor speed of CPU (inside MCU or MPU) how we can know which one is faster than another one? How can we know that?

The answer is we use relative comparison processor speed with reference CPU, what we call DMIPS (Dhrystone Million instructions per second or Dhrystone MIPS), reference CPU is DEC VAX 11/780 made since 1970. By comparison the same speed with DEC VAX 11/780 equal to 1 DMIPS. Relative comparison can use for compare with different Architecture CPU such as compare MSP 430 and ARM cortex M0 by DMIPS. (more…)