Do I have to upgrade my SMPS now, or is it okay if i upgrade it when I buy the new processor?
Better upgrade now please, I understand it is an expensive proposition, but it will help by extending the life of your components as well as improving the reliability of your system.
If the GX450W is pinching a lot, I suggest that you go for the Corsair CX V2 430W ~2400/-.
Hope this helps, Cheers!!