Here is a tidbit of wisdom we gained by using a FLIR handheld Thermal Spectograph on the rig and wiring and why, as mentioned above you need a spare 12v computer fan. (i haven't found this info anywhere on the net so if you are reading this consider yourself ahead in the game)

on the imgur link above i have included pics of the ASUS and Asrock mobos, the red circle you see is the component that can OVERHEAT and can cause long run mining problems. We found it to go over 70C in relative low ambient temp causing the PCIe slot BUSing to malfunction and freeze/hang the system.

Because we are utililsing the cold outside temp to regulate ambient room temp a fan pointed on that component is enough but you might consider installing a small heat sink to go with the fan for better results if you live in warmer environments.

pics of the 10GPU rig and more info coming later...