I've just put together a system featuring a Pentium 4 630+ CPU and an Epox EP-5EGA+ motherboard. I've installed the CPU and heatsink/fan combination as per Intel's instructions, and I'm not attempting to overclock.
I'm operating the system in an air conditioned room, and at this moment recording a CPU temperature of 45C and a CPU fan speed of 3590RPM. However, under heavy load, the CPU temperature increases to over 60C, at which point the CPU speed begins to throttle back. What is curious to me is that while the CPU fan speed changes from time to time, it does not appear to respond directly to the CPU temperature.
I've tried setting the CPU fan speed auto control in the bios to maintain a lower temperature, but this has had no discernable effect on either the temperature or the fan speed.
Does anyone have any suggestions as to what could be going on? Any help would be greatly appreciated.