Due to a few reasons i have decided to choose a 7850 over the 570 (power consumption and such). My question is whether or not this PSU (Rosewill CAPSTONE Series CAPSTONE-650-M 650W) (http://www.newegg.com/Product/Product.aspx?Item=N82E168...) could handle the wattage needed for this build if i chose to crossfire with a second GPU later down the road.
i cant remember from memory, but i think the hd 7850 actually only draws something like 130W.
my computer, which is fairly similar to yours, could 'theoretically' run on 270W. however, it's always a good idea to have a lot (about double the bare minimum [don't take my word for it, read around]) of headroom for PSU's, so i ended up getting the seasonic 520W, and my computer seems to run fine.
general rule of thumb; if your just building a normal computer, the recommendation will be fine. if however your using every spare sata port for HDD's, have something plugged into every pci slot, and are charging i-phones on all your usb ports simultaneously, you may want to invest in something a bit stronger than the recommendation.