Transmeta Corp., a closely held semiconductor designer, today unveiled two chips developed with International Business Machines Corp. that it said will use less power than comparable processors made by Intel Corp.

The debut follows five years of speculation about what the company, backed by Microsoft Corp. co-founder Paul Allen and financier George Soros, was doing behind closed doors. Linus Torvalds, who wrote the Linux computer operating software that competes with Microsoft Corp.'s Windows, is among the chips' developers.

The chips use software to perform functions that are usually handled by millions of tiny transistors. Transmeta said the benefit is reduced power usage, less heat, smaller size and lower cost. With the chips, a laptop can run all day, rather than two or three hours, on a battery charge, Transmeta said. Devices with the chips will be available by midyear, the company said.

One of the chips runs at 400 megahertz, uses the Linux operating system and is aimed at handheld devices such as tiny computers and wireless phones.

Another chip operates at 700 megahertz, runs Windows and is fast enough to challenge all but the most powerful chips made by Intel and Advanced Micro Devices Inc., Transmeta said.

Both chips have a "deep sleep mode" to extend battery life even if the cell phone or portable computer is left on, Transmeta said.