just upgraded my system to a 2600k, with 8gbs of 1600 Ram, and all the bells and whistles. Thing is I'm debating whether to buy another 6870 and do crossfire, or just sell my card(which I got for $130 from a sale a bit ago) and get a single 560ti. FPS are great... but not as great as I could...
I'm amazed how well this game runs on my q6600 @ 3.2ghz, 4gb ram, and HD6870. Autodetected at High settings, ran great, decided to put things on Ultra just for shits and giggles, and ran just as beautifully. 60FPS outdoors and around ~45 +- in towns. Really impressed with this game.
I'd be safe and buy a a very capable PSU. It's not too much of an investment and you never want to risk dirty power to your components. I'd do ~700watts maybe ~600 watts and the very LEAST to run crossfire.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150561
and
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150521
The first one is $20 cheaper but I can't really see any other differences except for the dual fans. Any help would be appreciated.