So, I had the chance to troubleshoot a few ATI Radeon HD4870 cards this weekend. With all three having the exact same issue, 2 are Sapphire 1GB QP editions while 1 is a Built-by ATI (I’m not sure how much RAM the BBA had).

In the end, all three cards have the exact same “problem” – Auto Fan control seems to have a very relaxed idea of what a good temperature is for idle. The card will continue to run the fan at 24% even when the GPU hits 65c+.

I can appreciate that these new cards can run hot. However, isn’t it better for the cards longevity to at least idle the fan at 45-55% to keep the temperatures a bit safer?

That coupled with the fact that ATI’s Catalyst Control Center isn’t exactly super-intuitive. In order to enable manual fan control you have to:
First, open the advanced interface on the Catalyst Control Center.
Next, choose “Overdrive” from the dropdown box on the upper left-hand side.
Click the not so obvious picture of a locked padlock, this will enable control of Overdrive after you receive a prompt warning you of the dangers of overclocking.

From there, you have to check the “Enable Manual Fan Control” box. Then you can set it from 24% to 100%. Once you’ve done that, you click the Apply button at the bottom of the window and the “Fan Speed:” reading will then show the current speed in a percentage which SHOULD match your manual setting. Note: be CAREFUL when setting a specific fan speed and make sure that if you’re decreasing the speed of the fan that you don’t set it too low or run a 3D application that will cause it to overheat.

If it doesn’t, that’s another problem.

I’ve also verified that the fan maintains this speed when 3D applications are running. Though, your mileage may vary if what I’ve read about some cards ignoring the Overdrive fan setting when a 3D application is running.

With all of that having been said, I cannot for the life of me find this supposed to exist powerplay control panel. Go figure.