How much Watts does my PC Use?

[Corkeye]

I have a 1000 watt PSU. I only use 750 watts. Do i use 750 watts per second or hour?

 

[sweenytodd]

750 watts = 1 Kilowatt

0.75 Kw/h

 

[Sakkura]

Your power supply only provides the power the components actually use. The power drawn from the wall socket is slightly higher, because the power supply is not 100% efficient (80-90% is pretty typical). So if your components draw 750W, your PC will actually draw around 830-940W from the wall.

Watt is the rate of energy use (Joules per second), so you can't say it uses 750 watts per second or per hour. It just uses 750W. Now, if you draw 750W for one second, that's 750 Joules of energy. If you draw 750W for an hour, that's 2.7 million Joule, or 0.75 kilowatt-hours.

 

[Sakkura]

750 watts = 1 Kilowatt

I think the only appropriate response to that is: Wat?

 

[sweenytodd]

lol, should be 750w/1000w = 0.75 Kw

 

[hunter315]

Watts is a measure of instantaneous power, KiloWatt Hours is the unit used to measure power consumed with a time frame, a load that consumes 1 kW for 30 minutes will consume 0.5 kWh, a load that consumes 500W for a full hour will also consume 0.5 kWh.

Your theoretical load will consume 750 kWh in 1 hour, but will be consuming 750W every moment in time, its difficult to clearly explain instantaneous power versus average power quickly.

 

[Sakkura]

Your theoretical load will consume 750 kWh in 1 hour, but will be consuming 750W every moment in time, its difficult to clearly explain instantaneous power versus average power quickly.

Compare it to driving. The number of watts is how fast you're going at any particular moment, the kWh is the distance travelled (over some period of time).