There are teraflop processors for the desktop now. Our standard 60 GFlop processors will take less than a minute to do a trillion operations. I don't see the computational bottleneck you refer to.
At least from a viewpoint of number of trials, we can easily replicate the number of trials evolution has to work with using an everyday desktop. Why don't we see comparable evolution in the desktop? There is some sort of magic to evolution we have not yet fathomed.