The FX 4300 is really a very weak CPU and his system needs more powerful CPU than GPU.
PSUs should not get on desired basis, it is the main component (coz it powers all the other components, it might damage the motherboard and CPU's VRM right away).
Srikanth, you shouldn't go under the choice of FX-6300 (this is a weak CPU too for 3D applications, but the minimal value).