Don't use nicehach pool for mining zcash.
I have 25% more profit in dwarfpool.

8 cards total (3 Nano, 4 RX480/4G, R9-290 Tri-X), ~2k/sec with undervolt/clock, 1.5kW.
I had ~ 0.012 BTC/day in nicehash, now I have ~0.015 BTC/day in dwarf.