For a beginner the different compilation modes of EiffelStudio can be confusing and I've heard people mention that they don't want to use Eiffel because it's runtime execution is considered too slow. The fact of the matter is, it is not slow! It is only slow when using all or the most aggressive contracts in "workbench" mode, which is by no means the result of an optimized final compilation. Such aggressive checking is sometimes what is needed when developing a new project, and sometime you can throttle back on such aggression. This article explains the various compilation modes and their pros and cons. The results will demonstrate that Eiffel is just as fast as C or C++.