I'm getting 500-600 dollars to spend soon and my computer is in need of a upgrade. I have a mobo that can only hold 1 graphics card. My graphics card is fine it is a gtx260. I have a q6600 2.4ghz , 4 gigs of ddr2 ram (its cheap 30$ ram lol so maybe Ill upgrade this too). I have a 750w psu so thats good too. I was thinking of getting the p55 but then that would mean I would have to get new cpu and ram to go along with it. So what do you guys think is the best for 500-600 dollars.