Bitmain said the upcoming Antminer E3 ASIC would offer 180MH/s of mining performance and consume 800w of power, which is an unheard of level of efficiency. To put that into perspective, our scrapped together “profitable” Ethereum miner pumps out 93MH/s from a combination of one R9 380, one R9 380X, one R9 390X, and one R9 Fury. That machine draws roughly 950w from the wall, which is profitable, but the gains are dropping, and it may soon be untenable to operate it. Our system isn’t the most efficient miner, to be sure, but it doesn’t make sense to spend the money on an “efficient” GPU miner with 10-series cards.
The biggest death knell for the GPU Ethereum mining market is the Antminer E3's price. Bitmain is asking $800 for each unit, which massively undercuts the current rate for a GPU-based system. To get 180MH/s out of a GPU miner, you would need six GTX 1080 Tis or nine GTX 1060s. In today’s GPU market, you’re looking at well over $6,000 (probably closer to $7,000 once you add power supplies and other equipment) to build a rig like that with GTX 1080 Tis, and roughly $4000 for the GTX 1060 rig. And that's you can get your hands on the cards in the first place.