Quote from: rikur on June 10, 2011, 03:12:39 PM

I don't think there's a single MOBO that can fit 5 high-end cards to it. The cards take two slots each.

Other than that, I Think your plan is good to go. Just keep the mobo laying flat on a surface; as heat rises upwards it becomes impossible to use a normal tower case with 3++ cards.

you will definitely want slot extenders for 5 cards and you will want to build a rack to mount them with some airflow space between them.

get slot extenders from cablesareus.com

and check out the different ways people mount cards here: http://forum.bitcoin.org/index.php?topic=7216.0