I am having a similar problem, although my fan is always at 2700+rpm. My Q9450 is overclocked to 3.2GHz on a EP45-DS3R board and I have the CPU Fan setting in the BIOS set to "auto." I never see the fan drop in rpms, and my temperatures are below 35C at idle. I just called Gigabyte and they weren't really any help. They say it is the CPU telling the Zalman to stay at that rpm. I think it might be because the Zalman might not be compatible with the BIOS control and that is why they supply the manual fan speed controller...which I didn't use. Anyone else with an opinion?