I'm sorry to hijack this tread, but can someone share lowest possible settings for S9 with Brains? One of my miner is able to run 500MHz@7.9 (10.5TH) with 880W consumption at ~240V. Others do 500MHz@8-8.2V with 930W+.  I guess you can go lower with frequency, but as far as I know 7.9 is lowest possible voltage for S9.