I meant GH/s, but I still find it hard to believe for a 600GH/s device to consume like 300W
At some point, a very credible source for such things, a member named 2112, is, hopefully, likely to advance some expert opinion on the whole issue of next-gen power efficiency on this or the other CoinTerra thread. Even then, nothing will be certain until the juice starts to flip the flops of the real live chips.