It is plain here that many people here haven't a clue as to how electral mechanical force works even thow there are differances how wasteful a P/S supply may or may not be,you want to look it in this way, power consumption kinda works like this let me use a car for an example, fuel system supply well be the voltage ok the engine well be the wattage ok and the road well be the demand on the P/S now you are cruising along getting great milage , nice flat road everthing is great right consumption of fuel is great, now you come to a down grade man milage is great consumption is low you are idling ok, now you come to a hill and you have to small of a motor in your car, now fuel consumption goes way up now its costing you mileage the motor is working hard , now the grade gets stipper your motor starts heating up your fuel supply is at its limits than suddenly bang your motor blows because you put to great of a strain on it, now if you had the perfectly sized motor in your car there would not have been a problem going upgrade there would have been a fuel consumption increase but thats ok cause your motor is running cool going down hill your idling again and on flat you are cruising the differance in motor size may or may not effect effiency of fuel supply, now to big of a motor is ok but that well effect fuel consumption and thats the just of it ,to small of a P/S can cost you way to much to run +it does't allow everthing to work correctly very wasteful and harmful the perfectly matched P/S is effientant and reliable and well run for years to large of P/S well do everthing that a perfectly matched P/S well do and last for years but may consum more power please excuse the poor spelling and grammer your friend Zinn2b