The minimal CPU requirements is blatantly wrong and his CPU should be doing just fine, this is not a bottleneck problem. I'm having a similar issue where I can comfortably play Arcade missions and the game set by default on the high settings and my CPU is considered to be "under" the minimal requirements. I checked and the problem is that this game has some weird coding issue that prevents it from drawing full CPU power. It's basically a reverse bottleneck.
You can't just go on saying that the problem is the dude's CPU and that he should spend 300$ buying a newer one when its quite fine.
