PSUs and power consumption

[terp4life2001]

Hello everyone,

I don't have much EE knowledge and I had a question about PSUs and their power consumption. I apologize in advance for any terminology mis-speak I'm about to use. If I have a 500W PSU but my computer isn't consuming that much power, does the PSU draw less power from the wall? Does it only draw what it needs or does it consume 500W and then somehow disperse the unused power. That would seem a bit silly to me so I'm assuming it's the prior, but I just wanted to know for sure.

Thanks in advance,

//Rob

 

[Bbq]

If you have a 1000 w psu and a 400w psu, but your computer only draws 300w max, then your power bill will be no higher. Efficiency also counts. The higher the efficiency, the less your electricity bill