Thought I would share this story ---

For several weeks I had been hearing a high pitched whistle when one of my dual opteron systems powered up. It would fade away and be gone by the time windows was running. It only occured during a warm reboot such as after a windows update that required a reboot. I never heard it after a cold reboot (several hours of being turned off). The system ran slow but I assumed that was because of two gpu tasks and 3 cpu tasks that boinc was running. When I suspended boinc the system ran better and I assumed all was OK.

I checked the cpu fans while they were spinning to see if they were causing the whistle and found one of the cpu heat sinks was no longer attached to the motherboard. The tab on the retainer broke where the HSF clip was to be attached to and the silver grease was all that was holding the HSF to the cpu.

I replaced the plastic retainer and the slowing down problem disappeared. Apparantly, the silver grease was sufficient to allow the system to boot into windows but not sufficient to allow it to work after boinc started the cpu tasks. The whistle was the bios warning that the cpu was too hot and the noise goes away after thermal shutdown. It was not easy to remove the HSF as the grease, which had NOT dried, had a good vacuum hold on the cpu surface.

Anyway, I thought this was interesting.