7. Internal Components: Capacity And Performance Take A Hit

Ultra lightweight computers don't have a lot of space for motherboards and other components. Small motherboards limit the kinds of CPU, graphics and memory chips that can be used. In addition, the very limited amount of space in very small laptops generally precludes the use of very high capacity/higher performing hard disk drives, batteries or cooling devices. In the end and because of all these limitations, ultra lightweight laptops are best suited to office applications and web browsing.

Note that with the exception of the Dell Latitude X1 the laptops in this review have Pentium M 753 CPUs that operate at 1.2 GHz. The X1 has a slightly slower M 733 (1.1 GHz). These are not the power hungry, high temperature workhorse CPUs you'll find in large and super large notebook computers, but they get the job done when your interests tend toward Microsoft Office, web browsing and FreeCell. Similarly, ultra lightweight laptop graphics components and memory need to honor CPU and supporting chipset limitations as well as power consumption and heat generation requirements.

A 60 GB hard disk drive in an ultra small laptop is considered high-capacity. Again, size as well as power and heat considerations prohibit anything much larger, at least with drives available on today's market. As a brief aside I like the way the Toshiba detects unusual acceleration and moves the hard drive's heads to a safe place. This is not unusual with today's laptops, but Toshiba does a nice job of letting you know what's happened.

Like a number of laptops Toshiba's Libretto U100 detects unusual acceleration and moves the disk drive's heads to a safe place.

The two 800 pound gorillas in the story of ultra lightweight laptops are battery capacity and cooling ability. Though the batteries for ultra light laptops can deliver impressive performance with low power components, they wouldn't do anywhere near as well with the kinds of power hungry components stuffed into luggable and desktop replacement notebooks. As for cooling, some tiny laptops have no fans at all. If they do have fans, as does the U100, their fans are small and move relatively small amounts of air per minute. So they can't dissipate large amounts of heat. If they use natural convection air cooling including conducting heat to external surfaces, similar limits are imposed. All of this reinforces the need to use low power/low heat components.

For the record, the Libretto U100's cooling system and fan seemed to function pretty efficiently. The laptop never got uncomfortably hot and the fan only turned on when I ran CPU or memory intensive benchmark tests.