Energy-efficient PCs have been around for a while, and laptops by their very nature use less power. But 2008 will go down as the year the industry made a concerted effort to build PCs that are energy-efficient (and therefore cheaper to run) and easy to recycle. To gauge their efforts, PC Magazine has created a new suite of benchmark tests and a new seal of approval.

Energy Efficiency
We tested laptop and desktop PCs under a series of energy-usage scenarios. Since your computer sits idle most of the time, we measured each system in the idle state, open to the desktop. We also took a reading after putting each PC into sleep mode, and another reading with the system completely off to test the power brick's energy usage. Finally, we measured how much energy each system consumed while it was doing real work. We used Maxon's CineBench R10 3D rendering benchmark to send a load to all of the processor cores and the memory subsystem. CineBench shows us how much power each system uses when it's working as hard as it can.

Recyclability
We can't measure the rest of the computer's carbon footprint, since shipping a PC to your house would be different from shipping it to our offices in New York City. So we asked each manufacturer to detail the steps they are taking to reduce waste and to recycle PCs.

Certifications
Certifications such as RoHS, EPEAT (Electronic Products Environmental Assessment Tool), and Energy Star 4.0 are important to the green PC story. Like software that requires a minimum of 256MB of RAM, they set minimum or maximum standards for computers on such measures as energy use and toxic components. RoHS and Energy Star 4.0 are directives of the European Union and U.S. governments, respectively. EPEAT is the work of a consortium of electronics manufacturers. Since all three are standardized, they are more comprehensive and specific in their assessments than the so-called green initiatives of the past. These standards aren't perfect, but they are a good start, and each set of criteria is important to the adoption of green computing in the industry. For more, see the sidebar "Know Your Eco-Labels".

Overall Green Rating
We took all of these factors into account in arriving at each PC's overall green rating, as well as other things such as performance benchmark numbers, suitability to task, and intangibles such as general impressions of each system.

PC Magazine GreenTech Approved systems excel when it comes to all of these criteria—they are energy-efficient, have the proper credentials, and have company policies that support recyclability. In this technology race, both the hardware and the company marketing it are important. Regardless of whether a system has been marketed as "green," the company itself must prove that it goes above and beyond to earn our PC Magazine GreenTech Approved seal.—Next: The Greenest Desktops & Laptops >

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