9.1 going to be slow...nvidia card take over ZCASH...
there are maybe 1/10th as many nVidia cards in mining operation as AMD, and they cost roughly 2.5x as much to reach equivalent hash rate. It won't even be noticeable.
More like 2x the cost for 1.7-1.8x the hashrate at the current development level of the competing ZEC miner programs.
That's assuming GTX 1070s - I'm not sure what the hashrate out of 1060s looks like.