How many 1080? What's the speed of a single 1080 please?
With CryptoDredge miner for single GTX1080 I get from 10.5 Mh/s to 11.5 Mh/s at consumption 160-180W depending on GPU model (Palit Gamerock Premium GTX1080 is the best for me)
What clocks are you running though? 160-180W... you're giving it a lot of juice. Unlikely to be the most efficient setup.
I run mine at 85% PL, +110 core +0 mem and that hashes just over 10 MH/s per card.