Back in the 70s, Kermit the frog lamented that it wasn't easy being green. My, how times have changed. In this new millennium, being green isn't only easy, it's practically expected. Neighbors sneer if you put out more garbage than carefully washed and sorted empties for recycling; grocery stores rake in what I can only assume are huge profits charging five cents per plastic bag; and those who carpool are rewarded with their own special lanes to bypass traffic congestion. Who can blame us, with the inventor of the Internet predicting that melting polar ice caps will one day force us to relive Waterworld. This push toward environmental friendliness has even permeated the PC industry. Most new components comply with the Restriction of Hazardous Substances (RoHS) directive, for example. The recent trend toward lowering power consumption and improving energy efficiency also lends itself to hugging the planet, even if it was mostly inspired by a desire to reduce the noise generated by Prescott heatsinks. There's no ulterior motive behind the latest component to hop on the green bandwagon, though. Western Digital's new Caviar GP hard drive breaks new ground as the first desktop drive we've seen designed explicitly to lower power consumption. Energy efficiency isn't new in the hard drive world, of course; mobile drives have carefully sipped power to conserve notebook battery life for years. However, the Caviar GP is a 3.5" drive meant for desktops, and that makes it rather special. There's more to the Caviar GP than its Birkenstocks, too. The drive packs a mind-bending 250GB per platter and is available in capacities up to a cool terabyte, making it the biggest drive in the Caviar line. There's a catch, of course. While most desktop drives spin at either 5,400 or 7,200RPM, the Caviar GP's spindle speed lies somewhere between the two, and Western Digital won't say exactly where. With its spindle speed shrouded in mystery, we couldn't help but wonder whether the Caviar GP's performance leans more toward the Tesla Roadster or the Toyota Prius. And what does a slower spindle speed mean for power consumption and noise levels? To find out, we've tested the drive against 20 others, with surprising results. Read the full review here.