i recently added another gpu to my system, and bought 2 Cooler Master Megaflow 200mm fans with it for better airflow. i installed the first one in the front, and it works great. my main card's idle temps have dropped 8 degrees, and while i haven't properly load-tested yet, max temps seem to have come down too. i installed the sli card at the same time as the fan, so these temps are that much better AFTER adding another card an inch below it. very impressed.
i planned on installing the other megaflow to the top exhaust port(?) but...i have no idea how to do that. in the case instructions, the illustration does not indicate which screw is used for mounting at the top. i tried every screw and they're all too small for the holes. do i need to buy separate screws, since the top fan is "optional"? the pictured screws are also pretty small, compared to the front fan which, mounted upright instead of hanging above everything, needed very long screws and plastic bolts (of which there are only 4 each). very confused about this
there's also the side port, which can mount a 120 or 140mm fan. one thing about sli...it is LOUD. would a side fan make an appreciable difference in further cooling the gpu's, to prevent their coolers from spinning up too high under load? and if so, care to recommend a good, QUIET fan for the job?