You're absolutely right, not sure why I dumbed down my example to a single instruction. Correct way to estimate this number is to feed and keep the whole pipeline busy.

This is actually a bit crazy when you stop and think about it. Nowadays CPUs are packing more and more cores per die at somewhat increasing clock frequencies so they are actually coming quite close to the GPUs.

I mean, top of the line Nvidia H100 can sustain ~30 to ~60 TFLOPS whereas Zen 5 with 192 cores can do only half as much, ~15 to ~30 TFLOPS. This is not even a 10x difference.