Hey guys, im new to the forum, so sry if this has allredy been asked before. I have 4870 and now someone is offering me cheap 4890 so im thinking of buying it and putting in crossfire, but im not sure if my power supply can handle it Im using LC Power 650w. I need to know that before i buy that card because investing more money in this computer is not an option for me. Oh and btw i have C2Q 9550, 4gbs of ram. Thx for your answers!!