I am planning on using an ATX power supply for a RAID cage with it shorted to the "on" position. Is there a rule of thumb for how much wattage each hard drive consumes, so that I do not underpower the RAID cage? I had heard 25 watts per drive, but I would assume there are further 5V and 12V amperage requirements the PSU must be able to supply, since it can't direct all its wattage just to what the hard drives need. Any help is appreciated. The cage would be expected to support 10-20 drives. And 20 would be an outside number, for sure. Thanks.