Intel engineers first began toying with a low-power microprocessor almost a decade ago, but their initial design was rejected by the company's top executives and the effort stalled soon after, an Intel executive said on Wednesday.

The initial concept behind Atom, Intel's new family of low-power chips for mobile devices, had its genesis in a research project at Intel's labs in 1999, but the idea was not "received enthusiastically" by Intel's senior staff, said Justin Rattner [CQ], Intel's chief technology officer, during a speech at Intel's "research day" in Santa Clara, California.

The idea behind the first design was to take the Pentium microarchitecture and adapt it to deliver chips that could perform well but reduced power consumption to just a watt or two, Rattner said. He didn't say why Intel executives were cool to the idea, but the chip's development stalled soon after.

Intel resurrected the effort in 2002, when the company's labs in Austin, Texas, designed new a low-power microarchitecture that it called Snocone. The goal, again, was to create an x86 processor that performed fast enough to run typical PC applications but while conserving energy use, Rattner said. It took considerable testing and simulation until the labs were convinced that such a chip could be built, Rattner said.

Rattner didn't say why Intel resurrected its low-power efforts, but the emergence of what looked like a viable competitor probably had something to do with it. The Silicon Valley start-up Transmeta created a stir when it introduced its power-efficient Crusoe chip for laptops in 2000. Crusoe used some novel software tricks to translate instructions for the processor and conserve power. Ultimately the chip didn't perform as expected, but it likely gave Intel a wake-up call about the need for a low-power chip.

After the labs convinced Intel's management that such a chip could be built, development started in 2004. That began a development process that would ultimately lead to the release of first Atom chip this year. The Atom family includes chips code-named Silverthorne and Diamondville, and they are destined for a new class of mini-laptops like the Asus Eee PC, as well as even smaller Internet devices. They will compete there with chips from Via Technologies, as well as chips based on designs from Arm Ltd.

Rattner claimed that Atom is the fastest processor consuming 3 watts of power or less. It was derived from the Core 2 Duo microarchitecture and is being manufactured using a 45-nanometer process.

Intel's research labs are now working on chips that will consume even lesser power, Rattner said. The efforts include improving manufacturing technologies and further reducing power leakage on chips.