hi, i normally use an HD 5550 and i also happen to have an HD 4650 sitting here. im not really a big gamer or gpu person so dont really know how it really works but is it worth adding in the 4650? never crossfired anything before so do you still need the little additional connector thingy? i dont think i have one if you do. also given the 4650 is older do they play nice together?