Here is how I did it.
I could see a difference but cannot reach 1.5T per 6 boards.
I am on 1.25T.
My ambient is 35C.
With proper cooling and 1.01-padrino FW you should be able to reach 1.5 TH/S. My modules have heatsinks on the VRM's and I have fans blowing on the bottom of each board.
Not sure how to change the date on the stats page, but I just took this screenshot.
Thanks.