I played it when it went on sale sa Dec. I played it with an i5 i saw fps dips and i saw a great deal for a used i7 so i sold my i5 and bought the i7 4790k and when i played this games again no more fps drops, i think this games loves more cores or higher clock.
PS: there is a multiplayer mod for this game and its for free assuming you bought this games on steam.