Hey man this is incredible!!!
With stock bios I have only 505Hs per card, now about 670-680Hs 1000/1600-100mV trixx for 4x r9 380 -530-540w power consumption
My rig
G1820
B85 asrock
4GB DDR3
HDD 250GB
USB extender x4
4x r9 380 nitro
CM v850

win 7 64 bit with 16.9.2 driver

This is a great result  Thanks a lot