The new Mac mini uses an advanced power management system leveraged from technology that makes the most of battery life in Apple’s MacBook family. This allows Mac mini to use dramatically less electricity – up to 45 percent less power at idle than its predecessor. And it makes Mac mini the most energy-efficient desktop computer.

Dell also introduced its first “hybrid” PC that is about 80 percent smaller than a standard Dell desktop and consumes up to 70 percent less energy – Dell’s greenest, most power-efficient consumer desktop. However there are negative feedbacks on this one(even on Dell’s own web site): Tacky looking, overheated constantly unfortunately.