As I type GPU is beter then BTC mining  if you are usa located.

I pushed this concept for about 13 months  and it has come to full bloom at the moment.

So  yes 100 zotac  mini nvidia 1070 cards will do  40000 sols of zcash 

gross net of 8125 usd per month

100 cards can be had for 35000 usd

six card rigs 
would mean 17 of them   roughly 4000

some racks and you are  setup with 40000 usd in

you would use  14 kwatts  about 10500 kwatts per month.

so at 10 cent power 1050 power bill.

net  8125 - 1050 = 7075  which means all gear should  be paid off in six months  if you have warehouse/barn/free space.

not many businesses  that good.  of course renting a space   means $$$  but   a  commercial space   means better power cost.

no btc deal on earth offers this anymore.