ҹ1000

The empire strikes back with an energy saver

INTEL has no intention of taking threats to its domination lying down. As
Transmeta
(see “Quicker, simpler, smarter chips”)
launched Crusoe, Intel released a version of the
Pentium processor designed to extend the battery life of faster laptops. The
SpeedStep Pentium chip plays some clever technical tricks to save on battery
power.

Laptops often make batteries last longer by using processors that run slower
than those in desktop PCs. But SpeedStep will run at desktop speeds of 650
megahertz when plugged into the mains, then slow down to 500 megahertz when
switched to a battery. This reduces its power consumption from 14.4 watts to 7.9
watts.

Consumers will pay a high price for this innovation: many computer
makers—including IBM and NEC—will sell SpeedStep-based laptops for
around £3000. Intel’s Northern Europe director David Hazell insists the
new chip is worth the extra money: “You can watch a full-length movie on the
move,” he says, demonstrating a SpeedStep laptop playing The Matrix on
DVD. But New Scientist has discovered that SpeedStep’s savings are
small compared to the power consumption of a laptop’s DVD drive—so users
may still not be able to watch a whole movie on one set of batteries. The
highest capacity lithium ion batteries for laptops can deliver around 20 watts
for three hours if the screen is dimmed and you don’t use the hard disc too
much.

But if the PC has a DVD drive, it consumes an additional 10 watts and must
run continuously while playing a movie. Many feature films run for over 2 hours.
The Matrix runs for 131 minutes. So how did Intel get a laptop to play
the whole movie on the move? “I haven’t actually tried it,” Hazell says. “You
would need a spare set of batteries.”

More from New Scientist

Explore the latest news, articles and features