installed the suspected card in my Win 8 and it immediately booted a low res desktop. Nice! right clicked the desktop to set bigger res and immediately black screen and monitor complaining about not getting signal, same symptoms as on Linux so i guess i can safely conclude i fried that card. Did not do any deliberate overclocking or undervolting yet but maybe it was the 74 degrees / I=17 that did it. Anyway the cards were not making any ROI with BTC down (and therefore the alts as well), high power costs over here and running below targets.