Title says it all really. Basically I'd like to know if power load on a power supply is the only thing that affects the amount of heat it generates. For example, will a 500W PSU generate the same heat as a 200W PSU if they are both connected to exactly the same equipment?
Perhaps a 500W is more efficient and so doesn't generate as much heat at a given load? My main reason for asking is just out of interest but it's worth knowing these sort of things when I'm choosing components for a micro PC I'm building.
P.S. I don't suppose anyone knows where I can get hold of the JRex range of tiny single board computers?