i am about to install a 7950 into my pc, upgrading from a gt610 (which is only a $40 gpu and sucks at everything) and i only have 2 fans in my pc, one on the front for the hard drive, and one on the back, for idk what, and of course my cpu fan, installing the 7950, do i need to get more fans? i can get 2 more on top and one on the bottom, should i install 2 more to keep my pcs temps lower with the 7950?