Question about power supplies

[BirdDad]

or does it just draw wattage according to what you have in your computer?
Example I have a 500w power supply but my computer is only drawing 300watts does the power supply still draw 500 watts from the wall?

 

[montag451]

It will just draw what is needed - but note that some cheaper brands quote the highest output possible from their psu as the rated wattage.
Whereas most reputable, more expensive, named brands will usually give more wattage out for a short while if needed.
Check the specs for more details.

 

[MarcVenice]

What he seed. Also note that more reputable, more expensive, named brands will usually also have higher efficiency's, so if your pc needs 200W it will actually draw 240W or so, where as a cheaper no name brand might be drawing 250-260W to deliver the same amount of energy to your PC, since it wastes more energy producing heat

 

[bigsnyder]

The advertised rating is usually the peak wattage it is capable of delivering, though as we
all know some manufacturers are more honest than others. Check the PSU reviews here
and at HardOCP. Tomshardware used to do some hardcore testing, but that has been a few
years ago and many of those models are probably not available.

 

[Puffnstuff]

I have an enermax galaxy 850w ps that is only drawing 220w from the wall right now. If all of my hd's were to wake up and start pulling power then that would change just like if I plugged anything else into my apc and turned it on. On modern ps's the amps are the most important rating and a quality ps will have high amp ratings on all the rails. Not all ps's can maintain their amp ratings across multiple rails at the same time so make sure you check them out thoroughly before you buy it.