When it comes to this game (and most games in particular) a CPU with powerful single threaded core performance will yield the best results. In terms of AMD vs Intel (currently available tech not some far off future tech) Intel is the best performer in this category. They simply outperform any of the AMD processors in single core performance raw horsepower and the hyper-threading is icing on the cake if you go that route but it's not entirely necessary just for this game.

An intel i5 outperforms any AMD FX chip made to date. Go with one of those. If you're on a budget go with a slightly older generation i5 to save cash because even older gen i5's will outperform an AMD FX chip.