"... so, I thought, why not?"

I took this as a "given", which may have been a mistake.

A friend of mine said that it would be doable; but, he didn't specify that his office was using 3ware cards.

Being RAID-6 ready, and supporting online expansion, I didn't dig into the details, and assumed that these cards were "state of the art", or close to it.

As far as I can see, each array must be fully controlled by a single card. If that's the case, I should've used a single 24 port controller, and I wouldn't have needed to base this around an SLI board.

Plus, a single controller would only need one backup battery - an option I have not yet purchased (about $110 each).

I might consider sacrificing long-term flexibility for a big, honking card. Anyone have a 24 port (not PCI-X) that they'd like to trade?