I have just posted thermal measurements as a comment to bug 488152, of which this is a duplicate. My measurements and long term experience suggest that passively cooled cards can and will die under the prevailing conditions. A "medium" rating seems to underestimate the problem a bit. I actually discovered the specific issue due to such an incident (though the fried card was an Nvidia with closed driver under karmic).
I have just posted thermal measurements as a comment to bug 488152, of which this is a duplicate. My measurements and long term experience suggest that passively cooled cards can and will die under the prevailing conditions. A "medium" rating seems to underestimate the problem a bit. I actually discovered the specific issue due to such an incident (though the fried card was an Nvidia with closed driver under karmic).