How we test laptop power consumption

Our laptop and desktop computer power consumption tests consist of running the system in four modes: Off, Sleep, Idle, and Load. To collect the data, we use a Chroma 66201 power meter.

While our test closely follows Energy Star standards for testing methodology, we have added a Load test to better reflect real-world usage.

Additionally, we break systems down into two categories for testing. Performance systems have discrete graphics cards, and use a gaming test for the Load test, while systems with integrated graphics, which we call Mainstream, use a general multitasking test.

Powered-off test:

1. The "test system" is powered off (shutdown) for at least 1 minute, but remains plugged into a wall outlet.

Idle test:

1. Boot the system into the operating system.
2. Confirm that the system has an active Internet connection.
3. Leave all active launch programs turned on.

Sleep test:

1. Put the system into standby mode, by way of the Windows Start, Shut Down buttons.
2. Let the system sit in standby mode for 5 minutes.

Mainstream load test (for systems with integrated graphics chips):

1. Reboot the system and make sure it is powered on, booted up, and logged into the operating system for at least 5 minutes.
2. The only applications, and so on, that launch should be those that launch automatically during system start-up.
3. Once it boots into the operating system, confirm that the system has an active Internet connection.
4. Launch the multimedia multitasking test.

Performance load test (for systems with discrete graphics chips):

Reporting results

The individual tests are weighted as follows, and multiplied by the national average cost of a kWh of electricity, currently $0.1135, to provide the average power consumption and estimates annual energy cost.