I'm assuming 480GH is the desired aggregated speed from at least 4 units? That's about 275MHz, which is pushing pretty hard. Some people reported taller feet and under-board airflow helped increase stability. The actual limit on this board is thermal derating of the main regulator, which is the rectangular add-on board in the corner by the pot. Keeping that cool will also help.
Yes the fans on these are pretty crappy and I won't be using them again.
They say max rate is 480 gh/s per each unit. I have multiple units, it would be nice to operate at around one terrahash per pair. I noticed as well a lot of heating in the power regulation modules. I guess I am going to have to make a plan as I don't really like the thermal cooling system.
Cheers