mdude, what are your ambient temps in the outdoor rig? I've been able to gather more information on the card now, overnight it ran ok but ambient temps where the rig is were in the 40s-50s F, so that's to be expected. Today is our first warm day in a long time, ambient temp is 74F at the mining rig and the 5870 in question has had to throttle back to a 790 clock speed to maintain 62C at 75% fan. Two of my reference 5870s are still chugging along at 950mhz, with fan speeds of 65% and 49%, and gpu temps of 62C. I am wondering if overheating is a known issue with this model of card (HD-587X-ZNFC). Will try another airflow improvement to see if that helps any, but suspect this might be a heatsink/possible warranty issue.
I don't have a thermometer down there, so I don't know the ambient temp. I can tell you the % fan rate is different than the others. It runs automatically in the 60%s or so to stay in the 60Cs, where as the others are 40-50. The RPM is different too, can't compare them. I run at 900/300 stock voltage.
