hi, i have been gifted a asus m5a97 pro for only £28 !!! i have a phenom II 550 oc'd atm, and i have a single gen 1 5770, the mobo has a second pcie 2.0 x 16 (x4 in x-fire) will this be enough bandwidth for a second 5770 with bridge. as it will only cost like £70, or will a 6770 work x-fire with my 5770.