February 6, 2006 4:35 PM PST
Quest for power control moves beyond the chip
One technique involves dedicating a voltage supply for both the CPU (central processing unit) and the cache memory. The other integrates voltage regulators onto transistors to improve efficiency, Justin Rattner, chief technology officer and a senior fellow with the company, said in a keynote address at the DesignCon 2006 conference.
The introduction of Intel's 90-nanometer manufacturing technology in 2003 made the world's largest chipmaker realize it had to do something to get control of the mushrooming power consumption of its processors. The Prescott Pentium 4 processor released in early 2004 consumed more than 100 watts of power at maximum performance, and plans were in place to go even further, Rattner said.
"We thought at the time we could approach 200 watts," Rattner said. However, the PC industry balked at the cooling requirements that would have been needed to prevent 200-watt processors from melting systems, he said. And the 90-nanometer technology was more prone to electrical-current leakage than previous manufacturing technologies, making 90-nanometer chips hot even when they weren't running at full power.
As a result, Intel had to drop its focus on making faster and faster chips and instead embrace low-power designs and energy-efficient manufacturing techniques. It plans to switch to an entirely new chipmaking architecture later this year that minimizes power consumption.
"Now we're looking at power in the rest of the platform. The CPU is in relatively good shape," Rattner said.
Intel is experimenting with separating the supply voltage sent to its processors, Rattner said. Under this plan, the CPU would have a dedicated supply voltage and the cache memory would have its own supply. This would allow system designers to remove integrated circuits that regulate the amount of voltage supplied to those components in today's systems, freeing up space on the motherboard and eliminating excess sources of power consumption, he said.
Another way to reduce the power used by the chipset and the various other components on a motherboard is to build digital voltage regulators right onto the chip, rather than using analog components from other suppliers, Rattner said. Intel first discussed this project at its Intel Developer Forum last August. Digital regulators can react to changing voltage requirements more quickly than analog components.