Hmmm...Ive found that the major bottlenecks on lower end stuff is actually the IO DB writes/reads and not so much crypto related stuff. Sure it has a positive effect if you can speed it up, but a good 70%+ of optimizing I do is how to get data over the IO quicker and more efficiently.
That was like word for word what Bytemaster said in this youtube video heh:
http://www.youtube.com/watch?v=bBlAVeVFWFM