My rig with 6x GTX1070 is mining ZEC with a total hashrate of about 2900 Sols/s.

what`s your oc settings ?
Core +190
Memory +1200 (I´m running linux, so this value should be +600 in Windows)
Powerlimit 150W
I was like WTF for a second. Why is that difference between win and lin?
Cause in linux your setting for memory is about GPUMemoryTransferRateOffset
So for basic, transfer rate of your memory = Memory Freq x 2
So OC on Windows will be
Core +190 / Memory +600
What is your model by the way +190 on Core seems impressive ...