I'm just finalising a new build and have decided on the ASUS Sabretooth P67A mobo. The review states that a downward facing CPU fan is required to help cool the board. Is this really neccessary? What experience have you guys had with CPU coolers on this board? Looking to clock a 2500k to 4.8Ghz, so need a decent cooler. Was set for the Noctua NH-D14....but now?