The ones that fit in the place of a PCI slot.
I have a pretty standard system, dell optiplex 240, I have upgraded to 1g. and 2 40g hard drives. I am worried about overheating, and was going to place an auxillary fan somewhere inside the machine, but can not find a place to mount, or a power supply. Does anyone know where to find a place to plug in an auxillary fan, (i'll find a place to mount when i know where to get juice), or would it be ok to splice into the existing fan, (i don't like that idea). What is the best way to go about this?