The new ones are pretty energy efficient but every Lenny & Carl have them.
Jimmy
I guess I will take that chance with power usage and rig 5 of the systems up, I see the most profitable coins to mine at the moment with daily average difficulty fluctuations is ETH/ETC/Decred/ZCASH.
So 5 rigs with 4x 280x cards in each one would equate to 20x 280x GPU's
I've done an estimation by using some calculators and rough hashrate estimation for ZCASH mining is 4300 sol/s with all 5 rigs going, sounds pretty good doesn't it ? To me it does.