I've been gathering parts for a new computer and I did some research and found that the Radeon HD7870 can play most games on high settings. I've been using Nvidia cards for a longer amount of time so I trust their cards more (so don't yell at me because "AMD is the shit" because I like nvidia more. Also, what is the amount of watts i should use in the card because everyone is saying things like "500,350,700,100,800, etc."