
30ghs with 120 chips ? What's the hash-rate of single chips ?
95 chips. That'd be 315.789473684211MH/s per.
If their 4.2J/GH number is correct, each chip is dissipating 1.3W. They aren't going to require anything special at all for cooling, likely small BGA heatsinks with pressure sensitive thermal adhesive would be fine.
95 chips = 30GH/s @ ~125W?