We always want to compare different types of MCU. If we look at PC processor industry it is becoming almost impossible tas objectively to compare two different processors as they are different in design and even have different number of cores.
But lets go through few characteristics that are used for comparing different embedded systems.
IPS
Instructions Per Second (IPS) is also known as MIPS (Millions Instructions Per Second) or even BIPS (Billions Instructions Per Second). Usually this indicates the rate of fastest instruction like NOP. So this is more marketing hype than a objective characteristics.
OPS
Because of IPS disadvantages there are OPS characteristic, which describe the execution times of a mix different instructions. Usually wee see FLOPS – floating point instructions. This represents heavy applications such as simulations or finite element analysis. But OPS has a problem two… it is dependant on instruction mix used. So comparing isn’t accurate from MCU to MCU.
Benchmarks
This seems to be the the only one way to be independent characteristic. Benchmarks are short programs like sort algorithms, and are used to compare functionality of equivalent code on different MCU’s. The problem is that there is no standartized benchmarks and it would be hard to do as it depends on programmer and compilation tools used. So it is usually up to you to run your own benchmarks for comparing and discovering which MCU will run code more efficiently using available tools.
Some interesting benchmarks you can find here: http://benchmarks.caxapa.ru
