power supply fan

i noticed my psu fan running a bit fast during boot up, which makes loud noise... but when the computer enters windows (im using windows 7 ultimate 32 bit) the psu fan slows down and those mixer noise like is gone.. i checked and i confirmed the noise came from the psu fan.. can anyone help me with this?

Hi cognag05 & welcome to Windows 7 Forums
Many power supplies have a automatic thermal control of the power supply fan: they reduce or increase its speed based on internal temperature without any intervention required by the rest of the system.

thank you for the fast reply .
so it is normal for a psu fan to run a bit fast during boot up even if the computer has been shut down for the whole night (the temperature i believe is not high at all) and back to normal speed when it enters windows?

Yes many do on boot, depending on the Motherboard the CPU fan can and on some PCs case fans can, if your concerned about your PSU fan i would monitor (watch and listen) to it over a few days

thank you
guess it solves my problem

Good , You may like to know some PSUs (eg Enermax here > http://www.enermax.co.uk/products/po...olution85.html) have a fetcher that the PSU fans run on for up to 60 seconds after system shut down to help cool the system.