Theoretical peak FLOPS per instruction set: a tutorial

Abstract

Traditionally, evaluating the theoretical peak performance of a CPU in FLOPS (floating-point operations per second) was merely a matter of multiplying the frequency by the number of floating-point instructions per cycle. Today however, CPUs have features such as vectorization, fused multiply-add, hyperthreading, and “turbo” mode. In this tutorial, we look into this theoretical peak for recent fully featured Intel CPUs and other hardware, taking into account not only the simple absolute peak, but also the relevant instruction sets, encoding and the frequency scaling behaviour of modern hardware.