The performance of a microprocessor is a measure of its efficiency in terms of the amount of useful work it accomplishes.

Equation

The performance (time-to-execute) of a certain finite workload is the reciprocal of execution time.

The total execution time, , required to execute a specific finite program is.

Where,

• IC is the instruction count
• CPI (), the average cycles per instructions.
• is the clock speed

Thus, the performance of a microprocessor can also be defined as.

Note that for the sake of brevity, sometimes the instruction count is omitted when referring to the performance of a fixed portion of code. In other words, when the instruction count is fixed because the program is not being recompiled, it is sometimes omitted from the equation. However, doing this ignores the fact that recompiling code can have a positive impact on performance.