Power consumtion

[LeChuck]

If I have a 450W PS that means I actually consume 450W/hour? Or the sum of all devices installed, so maybe something like just 300W? In this case, how can I find the real power consumtion of my machine (except reading all the power written on each device's case)?

 

[Rick]

There are power calculators online, which add up estimated power consumption of components, but there's a lot of factors involved and it will be impossible to get an accurate measurement. Even if you accurately calculate the total potential consumption of your components, how would you ever measure their real-world power consumption? It isn't like your system runs on full load all day long... There's power scaling, drives spinning up and down, optical drives not being used regularly, fans slowing down and speeding up based on temperatures, a CPU that isn't always crunching megaflops of data and a video card that isn't always spitting out intense 3D graphics....

If you want accurate results, your best bet is a load meter, like a relatively inexpensive "Kill A Watt" .

 

[DelJo63]

The rating of a power supply is the LIMIT of how much it CAN provide to
the devices attached. When running at full capacity, it will also then
consume at least that much plus a 1-2% extra for losses
(ie: nothing is 100% efficient). At lower outputs, it consumes correspondingly less.