When i start up my miner both cards run at full blast and then maybe a day later or less 1 core clock seems to have dropped off back down to the minimum 500. I switched the cards around and tried some various force commands but the issue still occurs. Heat related? Bad card? Software? I don't think its hte card because I switched their slots around and it still seems to the #2 slot. Its well ventilated and in basement in the dead of winter and their temps never reach extremes.
I'm using Genoils miner with the set up instructions (pretty much the standard setx for any miner) via ethermine.org.