I've been using a Radeon HD 6800 GPU for a while now, and it's been running fine until just recently when upon booting up the fan became very loud. I can't think of anything I've done recently that could be affecting the fan speed.
I've tried changing settings with MSI Afterburner and the AMD Vision Engine Control Center using the overdrive settings. I am able to change the listed fan speed % settings, but the RPM stays around 4600, even when I turn the fan speed all the way down. The GPU temperature is low, so it's not an overheating issue. After having this problem I updated my drivers with no noticable effect.
I'm running Windows 7 Ultimate 64 bit, and can provide any other information if needed.