has anyone try to overclock it above 425 Mhz? i run it on stock fan with temps 53/49 and c the fan at full speed about 3960 rpm and no x on acic chips and about 1375 Hf/s when i try to go above 425 still i have no hardware errors but my hash rate drops at 1200 Gh/s or lower? any explanation for that?? and my s5 looks rock solid having it run for more than 4 days at 425Mhz
P.S. i have allready ordered 2 delta fans  http://www.ebay.co.uk/itm/271775072487?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT