Battery saver: ATI graphics chip cuts power demands

The new chip, dubbed Radeon Mobility, pairs ATI's desktop Radeon 3D graphics technology with variable voltage and clock speed. The built-in variability allows notebook PC makers to design machines that lessen the power requirements of the graphics chip when running on batteries in order to increase battery life.

With the chip, ATI (atyt) is following the lead set by chipmakers Intel (intc), Advanced Micro Devices (amd), Transmeta and even Via Technologies' Cyrix unit, all of which have built power-saving features into their processors for notebook PCs.

Intel's SpeedStep technology reduces the core voltage and clock speed of mobile Pentium III chips when they're running on battery power; Transmeta's LongRun power-management technology continuously varies voltage and clock speed depending on the applications being run.

ATI, which claims a 57 percent share of the mobile graphics market, appears to be the first graphics chip vendor to introduce variable voltage technology. The Thornhill, Ontario-based company will look to the chip to help it maintain that grip in the face of competition from rivals Nvidia and S3 Graphics. Nvidia announced its new Geforce2go notebook chip last November. S3 recently secured a new design win with Sony.

The Radeon Mobility will work to save on power by varying its voltage and clock speed from a minimum of 1.5 volts and 66MHz to a maximum of 1.8 volts and 200MHz. Additional power-saving features include the ability to shut down "blocks" or features inside the chip, such as the 3D engine, that are not in use. Built-in peripherals, such as an LCD controller, also save power.

"If someone is on a plane, they might not need that (200MHz)," especially for using e-mail or creating Microsoft PowerPoint presentations while a portable PC runs on battery power, said Darren McPhee, a product manager in ATI's mobile business unit.

When running on battery power at 66MHz and 1.5 volts with its 3D engine shut down, the Radeon Mobility, with 8MB of Double Data Rate Synchronous Dynamic RAM, consumes about half a watt of power. If the same notebook user were at home, plugged into a power outlet and playing a video game, the same chip would run at 200MHz and 1.8 volts, with power consumption rising to about 2 watts.

Notebook manufacturers will determine how the power-saving technology is implemented in each notebook. ATI has the ability to support "hot keys" that let users change the clock speed and voltage of their graphics chip.

Radeon Mobility is in production now. ATI reports that a number of PC makers are evaluating the chip. It should being to show up in a number of notebook PCs later in the year, McPhee said.

The chip is the first in what will be a series of Radeon Mobility chips, each of which will feature improved 3D performance, greater integration of features and new power-management techniques, McPhee said.

ATI will release more detailed information, such as pricing for the Radeon Mobility, at a later date.