I am following an interesting class on Languages for Scientific Computing (http://www.cs.utexas.edu/users/pauldj/lectures.html) taught by Prof. Bientinesi (http://www.cs.utexas.edu/users/pauldj/). Just a week ago he explained about the theoretical peak performance of a processor that is none other than: n_cores * frequency * ops_per_cycle_per_cpu. But, that is not the practical one.