I have modded my gpu bios, adjusted the mem clock and now i'm running just a hair under 800H/s. Sadly I don't see any option in the Gigabyte Aorus software to adjust the voltages to decrease wattage. Currently the gpu is drawing about 100 watts. I also played around with the intensity and worksize setting but all resulted in lower hash rates. All in all these results aren't that bad I think.
Did you manage to reduce your wattage? im running Aorus 570s and 580 about 750h/s for the 580 and 775h/s on the 570s. Im still tweaking the 580 as its new. What did you mod the bios to? according to GPU-Z mine run around 70W.