Long story short:  They aren't 1.7TH/s miners.  Only a small-ish minority of people have had them consistently run what they claim to, and I imagine these were in ideal conditions (climate controlled data centers). When I was running mine in a ~27*C large basement, the most I could get was about 1550-1600, and that was running fans full blast and chips still HOT.

It would be equivalent to the S5 being released as a 1.45 TH/s miner.