currently my mining rig has 3 cards in it and the temps are 90-92 degrees with 7 fans in the machine I was still freaking out when i first had it right up until someone told me to check the average operating temperature of the card, It turns out the particular cards I'm using are safe up to 117!!! degrees
are you insane???
I had an xfx 7950 that had a fan go out. While waiting on xfx to send me a new heatsink/fan (yea they send me parts) it was reaching 92c. I thought that it would be fine running a week at 92c. Well I was wrong. I woke up one day and that mining rig was off. I booted it up and smoke poured from the video card with 1 bad fan.
Moral of the story, keep your video cards under 90c for gods sake...80c if you want them to last more than 6 months.
What I do is put a box fan or circular fan on top of my mining rig blowing down, it gets the cold air right to the gpu fans where it needs to be. My 7970s dont go over 70c on a really hot day.
My 7950s dont go over 80c, the voltage unlocked ones rock a steady 73-75c