SAN FRANCISCO, USA: Intel began selling its new Core i7 processor on Monday, finally matching the lower power consumption and ability to handle multiple tasks offered by smaller competitor Advanced Micro Devices.

Intel is already one year ahead of AMD in offering chips with 45 nanometer features that improve efficiency and power consumption, but in some ways the Core i7 is playing catch-up to AMD. A nanometer is a measure of the circuitry inside the chip.

The new Intel chip, formerly code-named "Nehalem," has four processing cores on a single piece of silicon and automatically cuts down power usage when the chip is doing less -- both features that AMD has boasted.

Until now, AMD has argued that Intel strapped together two separate double cores and called them a quad core, while AMD has had a true quad core.

Each of the Intel chip's four cores can handle two different "threads," or processes, at once.

The new features translate into improved speed for such calculation-intense operations as video editing and games, without using more power, Intel said.

Analysts say these features are available with AMD's new Shanghai chip, but note that it serves only the thinnest slice of the market at the high end.

AMD buyers must wait until next year to get the consumer version for desktops.

Intel took the opposite approach, offering its desktop version first. That will be followed over the next year by versions for laptops at the low end and servers at the high end.

The power-saving process will mean more battery life for the laptop version and more performance and less heat for servers, where computer centers spend huge amounts of money for air conditioning.

Intel spokesman Bill Calder said later versions would shrink the chip further from the 45-nanometer process to the 32-nanometer process.

AMD plans to shrink its chips to 32 nanometers in late 2010, with versions in production in 2011.

Semiconductors are multilayer sandwiches, with the silicon alternating with metal. They are called semiconductors because the silicon layer can either conduct or not, acting as a tiny switch to turn a circuit on and off. This happens separately for 731 million separate switches, or transistors, in the Core i7.

Intel sells about 80 percent of the chips that run the world's 1 billion personal computers, while AMD makes virtually all the rest.