Emmmm no. At most get an extra 10-20% more then what you need. Too big of a PSU which you do not use actually affects the longevity of it. Also, why pay more electricity when you don't even need it? 10-20% is more then enough.
Totally agreed.
First an explanation of what exactly the efficiency of a PSU means.
The efficiency rating on a PSU is simply a rating for how well the PSU converts the AC power it recieves from the outlet to DC power the components of the PC can use.
So, for simplicy sake, lets say your PC components are drawing 100w of power. If you have a PSU that is 80% efficient, it will really draw 125w from the AC outlet.
I've seen people say that you take the Wattage rating of the PSU, and the efficiency is how much power the PSU can really output for your component. That means that a 500w PSU, rated for 80% efficiency will only be able to supply 400w. This is wrong. A 500w PSU should be able to output 500w to your PC components in one form or another. Efficiency has nothing to do with this.
Well if I have a PSU that is rated for 80% efficiency, where does the other 20% go?
Simple answer: Heat. Any electricity not converted from AC to DC is given off as heat.
Will there ever be 100% efficient Power Supplies?
I'm one that lives by the moto "nothing is impossible", so I'm not going to say flat out no. However, I will say that it is highly highly unlikely, and none of use will probably see it in our lifetimes or our childrens lifetimes.
If I have a 500w PSU, does that mean it will always draw 500w of power?
No. The amount of power drawn is determined by the components of the computer and how much they require. The amount of power drawn will only be equal to what is needed, and no more. If all the components of a computer require 300w to run, then the "load" on the PSU will be 300w and hence the power draw of the PC will always be 300w+Inefficiency no matter if it is a 500w PSU or a 1000w.
So what do the different 80 Plus ratings mean?
The basic 80 Plus rating means that the PSU is rated for at least 80% efficiency at 20% load, 50% load, and 100% load.
The 80 Plus Bronze rating means that the PSU is rated for at least 82% efficiency at 20% load, 85% at 50% load, and 82% at 100% load.
The 80 Plus Silver rating means that the PSU is rated for at least 85% efficiency at 20% load, 88% at 50% load, and 85% at 100% load.
The 80 Plus Gold rating meas that the PSU is rated for at least 87% efficiency at 20% load, 90% at 50% load, and 87% at 100% load.
The 80 Plus Platinum(bet you didn't know there was a Platinum) rating means that the PSU is rated for at least 90% efficiency at 20% load, 92% at 50% load, and 89% at 100% load.
Now, that doesn't mean that the PSUs perform exactly at those numbers, but they are close enough, and of course you probably aren't going to use exactly 50% load or whatever, but it is close enough to give a good idea of what a PSU is capable of.
A good article from Techpowerup.
