Electricity bill :-)

I was just wondering:
On the same hardware (motherboard/cpu/HD) will a powerful power supply (800W) consume more electricity than let's say a standard one (400W)?

Thanks to read!
rs232

 

no, it will only use the power than is needed to operate, one good reason to have a PSU that can provide more power than is required is to be able to upgrade

Edit: BTW: I have an Antec TP Trio 550W PSU but the components are only using about 300W

Edit: to find out the approx power your system is using, check this

 

It's all about it's efficiency as well - a 600W PSU with a 50% efficiency rating will need to draw 400W if it's powering 200W of components. A 600W PSU with an 80% efficiency rating will need to draw 250W to power 200W of components.

I think that's how it works anyway...

 

The majority of decent power supplies have an efficiency of about 70%, some are better.

 

I'm so glad this has been posted, was always to embarrased to ask this Q

 

ah good, this has kind of helped me too, knowing that my new one will run efficiently. Its rated 85%, and thats the highest sort of rating i believe. Or at least I have seen no higher, never the less, thanks, and yes i use that psu calculator, I have a rating of near 500Watts in total with my hope-to-be-finished system.

So if I was using 500Watts, the PSu would generate 575Watts sort of, and because it has 4 12V rails combining to 48A, it gives me a little more headroom too?

 

Many electronic devices are now using modern power supply design which has nnear 90% output/input ration. Please see this link:
Power Supply Efficiency in Active Mode

 

Just 2p-worth - I am surprised efficiencies aren't higher, modern psu's use switching techniques and low-loss components to reduce the heat output (=losses)..so I'd expect 90% or higher [as geek9pm suggests]- BUT this will be at rated output (or 70% of rated output).
. . . . .If you buy a 700w PSU and only use 350w the efficiency may not improve - however, with a small heat-loss you may not notice the losses ( why would you?), so in practice a higher-rated PSU is "probably" a better bet...also you should get a bigger/quieter fan, more modern design, more connectors for the future etc. etc.

---The answer to the Original Q about electricity bills is you won't notice the difference and a larger PSU has more capacity for upgrades and should be quieter if it has a large slow fan.