my 1080 ti's are pulling in a ton of  coin  mining zec and skein


so 2  1080 ti's   are   1300 usd   and will do 1300 sols  burning 400 watts

   4 580's 8gb   are   1000 to 1100 usd   if you find them  and will do   1260 sols  burning  600 watts

open you wallets and cross over to nvidia 


a small 2 card mobo

https://www.newegg.com/Product/Product.aspx?Item=N82E16813145007

you can add risers  and  go  4 cards

small psu


https://www.newegg.com/Product/Product.aspx?Item=N82E16817182351

and you are pulling in coin.  this  psu will do 3 1080 ti's