I have the rosewill blackhawk case a gtx 660 and a fx 6300. right now i have two front fans, one top fan over the cpu, and one rear fan. my question is do i really need the top fan? I don't want to take it out because i tied my zip ties pretty tight and i'm afraid i'll cut the cpu wire. are two front fans and one rear fan good enough to keep my hardware at decent temps?