PSU Question: If a PSU is rated at 450 watts? Does that mean 450 watts max output or 450 watts continuous output?

[LiLxJohnny]

I have an Antec 450 watt PSU that came with the Antec Case that I'm bought. However, I have a couple of concerns about this PSU but nothing concerning the quality of this PSU (it rocks )

However, my concern is the amount of electricity this PSU will drain as I plan to keep the computer that this PSU will be powering 24/7. Will this PSU drain only as much power as needed? or will it continuously drain 450 watts?

The system that this PSU will power will be a XP 1800+ or better, motherboard, DVDROM, CDRW, and a hard drive (80 gigs) and I know 450 watts maybe overkill. If it turns out that the 450 watts refers to as "continuous drain" than I will need to settle for a 300 watts as to keep the electricity bill as low as possible.

LMK Thanks

 

[AntecCSR]

It'll only use as much power as your system needs. So it's not drawing 450 all the time.

AntecCSR

 

[LiLxJohnny]

Great, I was hoping that I wouldn't need to get rid of this PSU .. Thanks! AntecCSR

 

[ianfan]

If your electric bill is a concern to you, you may want to check the efficiency ratings the next time you buy a power supply.

 

[Mark R]

Most PC PSUs have an efficiency of about 70%. (For every 70 W, they push out, they take in 100 W from the mains).
This figure is typical for every PSU I've investigated - some shady manufacturers talk about Power Factor Correction (PFC) improving efficiency (and quote figures like 95% efficient) - these are a lie. PFC does not improve efficiency.

For a computer like you specified, which would use 100 W for its internal components, it will draw approx 145 W from the mains.