Gonna be watching this thread, in case I can magically afford it in the next two days. Gonna depend on what my pool does to be able to fund it, but turning two X1 into 1.2TH would be pretty cool. Should be able to scrounge up some cheap waterblocks and tie into a big watercooling loop too! Exciting!
BTW. I need you to call me as I plan to run this off your PSU's. Dells be a rocking this farm so far, I see no reason to change.
Do you feel 2 will handle 3 boards? I do, as I have seen them pull 8's and 9's... your input is needed.
If they're looking at pulling no more than 400W per board, you could get away with two boards per PSU but three per two PSU load-balanced would be both safer and more efficient (as each supply would be operating closer to its peak point). Hate to be a shameless plug but we (the guys that make the Dell PSU boards minersource sells) should be started moving DPS-2000BB boards in about three weeks, which can source about 2500W reliably but require 200-240VAC input. There's a preorder group buy
https://bitcointalk.org/index.php?topic=637595.0 in case anyone's interested.