The short answer is: no.
RAID is for hard drives only, it does not affect the other parts of your PC that may be holding back performance. What you seem to be asking for is some kind of Power Rangers-style Megazord computer, and sadly, that's not how PC's work.
While it's technically possible to link computers together as a Beowulf Cluster
, that only works for certain, specially adjusted applications. It's not going to let you ram a bunch of Semprons together to make a machine that can play Crysis on Ultra.