A while ago I overclocked my Intel E4500 and ever since then the fan attached to the power supply is spinning very fast and loud for like a minute after turning the computer on. When the system is fully booted it returns to normal speed. I'm not sure if it's related to the overclocking but it appeared around the same time I did it, though I haven't increased any voltage in the cpu. If I reboot the system the fan stays normal speed so it only seems to speed up when the computer recieves a bigger amount of power when I turn it on.