What Does 87% Efficiency Mean for an 80 Plus Gold PSU Rated at 1000W?

[Hercuflea]

Hi,

When the modern 80 plus power supplies are quoted as being "87% efficient" on 100% load, does this mean that an 80 plus Gold PSU rated at for example 1000 Watts will provide 1000 Watts to the internal PC components, and therefore draw 1000/(0.87) = 1149.43 W from the wall? OR does it mean that an 80 plus Gold PSU rated at 1000W will only supply 870W maximum to the internal components?

 

[Svein]

does this mean that an 80 plus Gold PSU rated at for example 1000 Watts will provide 1000 Watts to the internal PC components, and therefore draw 1000/(0.87) = 1149.43 W from the wall?

Yes, it should (by definition) do so. Whether it really does, is another question.

 

[meBigGuy]

Power supplies are rated for their output power. But, since there are multiple voltages (and multiple loads) the output rating is generally a combination of loads that make the supply look good. I don't know how realistic the ratios (say ratio of 3.3V power to 12V power) are, so it's best to consider the output rating to be approximate.

 

[rbelli1]

Like meBigGuy says not all combinations apply. There should be an indication in the manual and frequently on the label what those limitations are (often in amps not watts). I would be skeptical if
1000W can be drawn by actual pc components.

BoB