Yeah this is kind of where I've been leaning because of the high CPU usage now due to the drivers. The CPU cooler is only a small fan with a moderate heat sink. The 12v rail amp idea is kind of interesting however. With only a bit of OC'ing (300Mh/s each) I can keep it stable for up to a couple of days before a reboot so I've been living with that for now. I plan to change out one of the cards with a lower power / hash one at some point anyway once I get another rig up and running. With the price ATM however it might be later rather than sooner.