with opensourse i get:
GTX 1070 - 49MH/s
GTX 1080Ti - 82MH/s
you are liyng with 70% more performace:
1070 49MH/s --> 68MH/s mean 38.5% more performence, near 1/2 from what you say

on my 5 1080Ti rig i get 410MH/s on opensource and daily revenue is 16.25$ on Denarius coin according to whattomine.com and 0.0002btc/denarius on cryptopia.co.nz so who will pay 275$+ for your miner and 2.5% when it need to mine with 5 x 1080Ti 58+ days to pay your 0.1btc, pay attention denarius coin since it was launch has just drooped. ty