Rig not performing 12 X Radeon RX 570

Why does my HiveOS Rig with 12 gpus mine less than a windows rig with 1 P1000 gpu and an i7 cpu? Also this same rig was running windows 7 with nicehash and only 6 gpus and was mining more than it is now?
Something is not setup correctly because according to the site I am mining @ 2.815 GH/s

Any help on how to improve the mining rate will be greatly appreciated.