But an interesting information coming from SiaTeam in response of this announcement
"The specs are in line with our most optimistic simulations for the SC1. If we can get the chips to run at 0.5V, we'd be seeing around 3.3 TH/s per 1000w" from Taek42 Developer
The fight begins
From my reading of Taek42's posts (sia dev)
Obelisk is unstable at 0.5V and stability is found at 0.6V delivering a 2.25 GH/w (833 GH total +/- 5%)