In GPU-Z, my ASUS cards' ASIC quality ranges from 69 - 76%, while both my XFX are >76%. My two lowest ASIC quality ASUS cards, 69% and 70.2%, require 25 more mV more at 1100 core clock while mining (825 mV). All the other cards are stable at 800 mV, including XFX cards which are clocked higher at 1175 core. There seems to be some correlation between ASIC quality and undervolting voltage, but at the moment, with such a small sample size, it is just anecdotal evidence.
How about you guys?
825mv and 800mv are outstanding numbers
my sapphire gpus being 78% asic quality cannot handle 825mv
have to run them at 850mv for stability