How Did Power Use Get So Crazy?

One way to make a PC more efficient is to redesign it from the ground up, the approach taken last year with several low-power, low-performance computers aimed at green-minded consumers, from new companies like enano, Koolu, and Zonbu. These PCs for the most part ran Linux variants and used ultra-low-power VIA processors. If your computing needs begin and end with sending e-mails and browsing the Web (as is true of many users), such systems can seem very appealing. Take the Everex gPC: When Wal-Mart stocked it for just $199, it sold out in record time. This Linux-based desktop purports to offer low power and ease of use to appeal to the masses, at a very attractive cost. But novice users are likely to be unfamiliar with its Linux OS, and the lack of compatible software at big-box stores will be equally frustrating. If these users want to expand their computing repertoire by, say, buying music in the iTunes store or using an Adobe video or photo-editing product, they can forget it.

FrontHP Compaq 2710p
$2,457 direct

This 2.7-pound convertible tablet can produce all-day battery life with its dual-battery combination. Though it isn't as powerful as some other tablets on the market, the 2710p is completely green, consuming the least energy among this crop of laptops and easily meeting Energy Star 4.0, EPEAT Gold, and RoHS specifications.
Alas, most standard PCs sold today are power hogs. How did this come to pass? Chipmakers pushed CPU clock speeds higher and higher in the new millennium's early years, turning PCs into energy junkies. Intel's processors reached their power-consuming zenith in 2004, with high-end Pentium 4 or Extreme Edition CPUs topping 135W, and PCs using them burning as much as 800W. But change was already in the works: Intel had been developing the Core architecture, with one goal being to cut of power consumption by more than half. Look for a mainstream Intel Core 2 Duo or AMD Athlon 64 X2 chip, both of which max out at 65W. If you don't need much CPU horsepower, AMD's 2000 series of dual-core chips tops out at 2.3 GHz but uses a maximum of 45W.

Today's CPUs include robust power-management features. Intel's SpeedStep and AMD's Cool'n'Quiet are similar methods for throttling CPUs, slowing clock speed when the system is idle. And extra cores don't double the power draw; multicore processors from both companies can self-regulate, turning off unused cores. It's nice to know you've got the extra horsepower—but only when you need it.

More recently, power supplies have come under the gun. For years, PC makers saved money by using cheap, inefficient units. The EPA turned that around with its 80 PLUS initiative, which helps domestic and foreign companies make power supplies that convert at least 80 percent of AC power into juice for your PC. The EPA's help lets Antec, Enermax, and Lite-On build better power supplies for less—-giving giants like Dell and Gateway affordable, efficient options. Watch for the 80 PLUS symbol on a PC's packaging to ensure its efficiency. Incidentally, modern units draw only as much power as the system needs at any given point.—Next: Toxic Shock >