Any guide to explain everything while purchasing CPU?

[DrMrLordX]

I still hear that AMD produces a lot more heat and is generations behind in technology. Do I stand correct?

On their AM3+ platform, yes. Things aren't so bad on FM2+, but AMD deliberately stopped trying to compete with Intel in performance on that platform, so your choices on FM2+ are pretty limited unless you are a rare HSA/OpenCL programmer. Even then, you may still be better off with the i7-5775C.

It would help if you could tell us more about the software you want to run, before anyone makes specific recommendations.