We try to work as well as we can with any company behind the scenes on Driverheaven because it benefits the end user -- you guys, you pose your concerns on our forum and we attempt to get the answers when we can. I have been noticing alot of discussion on our forums lately from members concerned about seeing 70-80c temperature readings from the ATI overdrive panel on their shiny new X800 boards. I posed the temperature question to one of ATIs top engineers, this is what he had to say. At over 100C or so at the die temperature, thermal issues and possibilities of permanent damage start being important (I would strive to keep it below 100C). Certainly by 125C, permanent damage will occur. Below, that, life expectancy is shortened with higher temperature, but you should be fine for a few years.

We test our boards up to 55C ambient temperature, and at that temperature, all of them work fine. Most computers have much lower ambient temperature, and the associated die temperature should be fine, except if there is a fan failure

ATI GFX Boards Temperature Myths Uncovered