Work out cpi and execution time instantly with clear inputs, formula shown and shareable results.
The iron law of performance: execution time is instruction count times CPI divided by clock frequency. All three terms are levers — better code reduces instructions, better microarchitecture and memory behaviour reduce CPI, and process improvements raise frequency.
Iron law
time = instructions x CPI / frequency; IPC = 1 / CPI
Base CPI reflects the pipeline's ideal throughput; stall CPI captures cache misses, branch mispredicts and dependencies. Separating them shows where to optimise.
Yes, on superscalar processors. Modern wide cores achieve IPC of 2-6 on favourable code, which is a CPI of 0.17-0.5.