No, capitalism is not more economically efficient than socialism as capitalism focuses the economic means in the hands of the few. Socialism seeks to bring the economic means in to the hands of the many, and as capitalism will never do this, it stands to reason that socialism is more efficient, no matter the time it takes.
In nearly all cases the free market (capitalism) is more economical and efficient. The only exception is public or limited resources, (e.G. Railroad tracks or highways) where competition is not practical or efficient. In all other cases the free market has proven to be far more efficient than state controlled or centralized planning.