When a PSU is RATED at for example 500W does that mean that it always used 500W's of power? Or is that only a load marker i.e. it will only handle 500W?

Also does having a power supply of double the wattage i.e. 1KW increase the PSU's lifetime (if used in the same machine)?

I'm trying to work out if its better to have an over rated PSU or if that would just waste power. I know that GOING for the efficiency ones will give the best energy savings but I don't see them LASTING LONG enough to make up the money that I spent on them in the first place.Quote from: Accessless on September 03, 2009, 12:26:23 PM

1. When a PSU is rated at for example 500W does that mean that it always used 500W's of power?
2. Or is that only a load marker i.e. it will only handle 500W?
3. Also does having a power supply of double the wattage i.e. 1KW increase the PSU's lifetime (if used in the same machine)?
4. I'm trying to work out if its better to have an over rated PSU or if that would just waste power.
5. I know that going for the efficiency ones will give the best energy savings but I don't see them lasting long enough to make up the money that I spent on them in the first place.