The quest for longer laptop runtimes continues—with mixed results, according to our latest round of laptop tests.

We tested laptops with two new chipsets in our latest Ratings of laptop computers (available to subscribers). Intel's new Centrino 2 promised better battery life with its new technology, and it delivered. Two of the Centrino 2 systems we tested with standard batteries—Sony's VAIO VGN-SR190 and HP's Pavilion dv4t (model information is available to subscribers only)—ran for at least five hours on a charge. That compares with about 4 to 4-3/4 hours at best on prior versions of Intel's dual-core processors. Centrino 2 systems also offered very good to excellent performance.

But watch out for the price. Adding a Centrino 2 processor to your laptop can boost the price by $100 to $200; the least expensive Centrino 2 model we tested was $900. Of course, if you need the longer battery life, play a lot of 3D games, or do video editing, it might be worth springing for the Centrino 2.

Notebooks based on AMD's latest technology, however, didn't fare as well. They were slower than Centrino 2 systems, and battery life was shorter too, lasting about 3 hours or less.

If you're in the market for a new desktop computer just for basic tasks like e-mail, word processing, and Web surfing, a machine with the Pentium Dual-Core processor should suffice, and will cost a lot less. For example, the Dell Inspiron 530, now priced at a mere $400, offers good performance and features, very good ergonomics, 2GB of RAM, and 128MB of video memory.

If you're looking for more, check our latest Ratings of desktops computers and Ratings of laptops. (Ratings are available to subscribers only.)

—Donna Tapellini