Wow, I have seen an #Bitmain #Antminer #S5 for 519 EUR which makes 1150 GHashes/sec. and may sound a lot. This is 0.45 EUR per GHash. Compared to my #R-Box miner with 32 GHashes/sec. it has 1.87 EUR per GHash. This means that the larger miner is more efficient (more coins mined for lesser money per GHash). Well, now you need to calculate energy consumption in: R-Box=30-50 Watts, S5=590 Watts.