Assuming you have variable speed fans. Depends on your motherboard. Usually in your BIOS under Monitor there is a setting for Fans and you can set what temperature you want them to kick in at and out or low at under the Custom Fan Speed. Motherboards have many different configurations in respects to different components just have to poke around a bit. If your MOBO fan speed selection is something like silent, normal, or ultra, something like that, just set it to ultra or high, or something on that variation. If all else fails try Fanspeed.