In 2007, Ecos Consulting, the Electric Power Research Institute, and the California Energy Commission decided to test the limits of energy efficient desktop computers. Focusing on reducing power consumption during idle and active modes, their goal was to create both market-ready and ultimate-efficiency computers that would still have good performance.
The team started by selecting the most efficient available motherboard and chips - one of the most important steps in creating an efficient computer. They used processors that can dynamically scale performance to match program requirements, saving energy when processing demands are low, and selected components with low electrical losses.
Next, the team reduced idle power consumption by an additional 25-36% by selecting efficient components. 80 Plus certified power supplies and efficient case fans saved about 7 Watts. Using a single, larger memory chip instead of two smaller ones saved another 1 or 2 Watts, without impacting performance. The team also specified a hybrid hard drive, which supplements the traditional spinning disk with a flash buffer, saving 5 or 6 Watts. New, flash-only hard drives, which have emerged since this research was completed, can save even more energy by eliminating the spinning disk altogether. Plus, these hard drives are faster than traditional hard drives, improving performance.
Putting everything together, the team found that nearly all of their prototypes had sufficient performance to run typical office software under the Microsoft Vista operating system, while consuming 40 to 70% less energy than Energy Star qualified computers.
This translates into a huge savings potential: if all U.S. enterprises adopted the ultimate efficiency computer, corporations could eliminate 11.2 million tons of CO2 emissions, save 16.7 billion kilowatt-hours, and save $1.67 billion in electricity costs.
Computers spend most of their time in idle mode, and efficiency improvements in this mode do not impact processing performance, so idle mode savings are an easy way to make a big impact.
Photo and Chart Credit: Courtesy of the California Energy Commission and Ecos Consulting