Heat Power

I am working on a circuit board simulation.  I have a quick question, does Solidworks use Heat Power load, defining it as the amout of power a chip uses, or is it rather the difference between the amout of power a chip uses and its efficiency? (i.e. - if a chip uses 100 W, and it is 90% eff., then do I use 10 W for the Heat Power load? It seems to me that if the eff. is 90% then one can assume the max dissipative heat power is then 10 W...?

SolidworksSimulation