FPS drop problem

Im building a pc for dota instead of playing at gamecafe, i have a question, what is truely factor affect to fps dropping problem, is that CPU, VGA, or ram. Thank you.
Ps: it seem like gtx960 is not good enough

CPU

what kind of CPU i should use, dear sir NeedforKill.

@amdemto1 said:
what kind of CPU i should use, dear sir NeedforKill.

some good intel with high core speed