Scousejoe :
Yeh its high rpm but my desktop is running as 20c it needs to be quiet, as it's a digital audio workstation
Usually the BIOS monitors the temperature and sets the fan speed to accomodate the heat.
What you can try to do to fix this is any or all the below:
1- Check your computer for dust collected inside on the board, fans, and the vents.
2- Update your BIOS.
3- Check what programs are running on startup and possibly try to reduce them as this makes the computer work more ergo overheat and make the fans work to keep the temperature stable.
I hope this helps.