but in reality i shouldn't have to overclock as it should be hashing at 1.2 TH/s minimum?
While i was tuning the boards to find their max. stable hashing rate, cgminer occasionally gets ZOMBIEs and doesn't recover. But once I lay off the OCing, they can hash stable and if one should fail, cgminer tents to be able to recover it automatically after 60 secs of 0 share submitted.
Interesting to know, i don't think i waited 60 seconds to find out if it would auto kick in.
also, are you running cgminer in linux? if so, which one would you recommend or doesn't it really matter?
also, is the sierra being damaged in anyway by setting the clock rate to 590? as i thought i read somewhere 612 was a sweet spot, i didn't fancy pushing it that far.