well, it's because your AMD's FX6100 "Faildozer" bottlenecks you. Change your CPU into an I5 or if your budget limited, to an FX6300, to get the full potential of your powerful GPU. FX6100 is a bulldozer architecture CPU which lacks so much L3 cache and it failed AMD so much that it turns out that it is the "blacksheep" CPU of the company. Even a first gen I3 or a phenom IIx4 will beat that poor CPU.