Equation: CPU_CLK_UNHALTED.THREAD / INST_RETIRED.ANY
Category: Efficiency Ratios;
Definition: Cycles per instructions retired is an average instruction flow measurement. Theoretical minimum of 0.25 cannot be achieved. The real limit for a given application cannot be predicted. Optimizing the code by changing source or compilation options changes the numerator and denominator. A low CPI value can be the result of a low cycle count or an excessive instruction count.