ok after a bit of researching and testing the best settings i've found for performance/noise/power economy

core clock = 890

vcore = 0.943

memory = 1500 stock

power limit or power control = -15%

fan = 50%

my system seems to consume 80 watts less than stock 180w vs 260w with power limit @ -15% that makes 430kh/s for a 100 watts  

will post about average temperature later but it seems to be around 50c