northbridge cooling aside form the stock heatsink is a MUST, i can not stress that enough.
if you dont put a fan on there its gunna over heat. even at stock its insanely hot.

i've said it before i'll say it again. no matter how cheap asus wanted this board they were absolutely retarded for not putting a fan on that northbridge.
and it would have costed them less than a dollar to do it.

hell 50mm fans are only like 3 bucks. go buy one, you wont regret it.

and you should seriously look into a heatsink and or heatsink/fan for the southbridge, that sucker gets hotter than hell too.