4 s-3s do close to 2th   1.8 - 2.0

they would use about 1480 watts for about 1.9th

the s-4 uses about 1380 watts for about 2.0th


Specifications:

* Chip Operating Voltage: 0.72V

* Chip Quantity per unit: 160

* Hash Rate: 2,000GH/s guaranteed

* Power Efficiency: 0.69Watt/GH/s at the wall

* Over clocking: About 10%, but not guaranteed

* 3U Rack  432mm*442mm*133mm

* PSU inside: 1400W, 80PLUS gold. Power line not included. You may look for one line with no less than 16A in your local market

* Temperature: 40-50 degree Celsius tested in the mining farm

* Fan Speed: 3900RPM

* Stable but a little bit noisy

* Ethernet connection, Stand alone

* Certificate Compliance: FCC/CE