I'm just curious. How does the intel stock fan works - does it rely on software (e.g. mbm, speedfan, etc...) to control its rpm or the motherboard sensors control it? because when i restart or turn on the system and immediately go to bios, the cpu fan is always at its maximum rpm.

http://support.intel.com/support/processors/pentium4/sb/CS-007999.htm

Intel HSF has built in temp sensor in the fan. Check the link above.

Intel thermal management is an open book to everyone, although not many people bother to check the website. In fact, there are only a few 3rd party HSF exceeds the stock unit.

My fan seems to stay constant at 3125 rpm using Sisoft Sandra and stay at that speed even when running the burn in module. I don't want to load any other utilities as it might change the fan speed. I want to see how the stock hsf reacts without using software to control it.