started on 10/2012 with 3x 7970. just use as heater, I have water cooling so its quiet. In several month I found that profitable. upgraded to 10+ 7970 and several 7870s.
Now I have 1.2THs in bitcoin and almost 20Mhs in litecoin.
Draws about 20Kw
Is your 1.2TH/s just in video cards or is there an asic under the floorboards somewhere?