To begin with, it's perfectly possible to increase several orders of magnitude the performance of a piece of code, you can Google for plenty of examples. In add

To begin with, it's perfectly possible to increase several orders of magnitude the performance of a piece of code, you can Google for plenty of examples. In addition, going from 1 sec to 0.5 sec is indeed 100% improvement. Given 0.5 sec = 1 ; 1 sec = x, then x = 2