Cpu switching for a computer.?

This is a fairly simple question. I use an Alienware M11x, core i5 processor. It honestly, compared to the graphics card, isn't that good. On the other hand, theirs a Toshiba Satellite, with another Intel Processor. I would just like to know, could I possible switch those out? And if you've researched into this M11x, would it make a slight improvement in performance?