There are plenty of questions about what a safe gpu temperature is, but these seem focused on what temperatures a gpu will survive at in the short term, regardless of whether it may shorten the cards life.
I recently ordered a video card that I need to be able to run under constant strain at work, but its longevity is very important. I would not have intentionally overclocked it, but to my surprise, it was the "overclocked" edition (Sapphire Radeon HD 5770) that arrived in the mail (doh!).
What temperature should I try to keep a GPU to, if I not only want it to survive today, but want it to live a long healthy life?
P.S. We will probably be buying other cards, and any other longevity suggestions are welcome, but my actual question is specifically about temperature.