How Much Power Does a Laptop Use?

Laptop EnergyThe cheap answer for how much power a laptop uses is, “It depends on the laptop”. In general you can expect a laptop to use quite a bit less energy than a desktop. The processors in laptops are clocked down to use less energy to ensure longer battery life.

A macbook pro (2008) uses about 40 watts of energy, but new computers are not only faster but more efficient as well. In netbook laptops the goal is often efficiency over performance as they typically perform simple tasks such as surfing the internet. Some netbooks actually limit their power consumption to under 10 watts under load! And you wondered why they’re a pain to use.

Another factor is the operating system. A computer running windows tends to actually run a few watts heavier than a computer running MacOS. Apple has certainly tried to create machines that consume less energy (are more green) yet provide a better user experience. When you start getting down to laptops with solid state drives and low processor consumption the display actually ends up being a big portion of the energy being used. This is the case with the macbook air, just as it is with the iPad.
The purpose of this post is to collect different kill-a-watt readings from various laptops so feel free to submit the power consumption results for your laptop in the comments! Here are a list of a variety of laptops and how they do while idling to give you an idea of how much power a laptop uses.

Idle Laptop Power Consumption

2012 Samsung Series 7 700Z3A-S03DE Ultrabook: 15 watts
2011 HP Pavilion dm1-3180eg Netbook: 6 watts
2011 11″ Macbook Air: 8 Watts
2011 13″ Macbook Pro: 6 Watts
2008 15″ 2.2 Macbook Pro: 40 Watts
2006 13″ 1.86 Macbook: 35 Watts


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