Chip designers look at low-power, high-perfomance processors

Intel, IBM, Sun Microsystems and Sony have all discussed their latest products and suggestions as to what might be coming next in...

Intel, IBM, Sun Microsystems and Sony have all discussed their latest products and suggestions as to what might be coming next in the processsor market, at the International Solid State Circuits Conference (ISSCC).

Chip performance has improved substantially in just a few years, but chip makers are worried about the large amounts of power required to maintain high levels of performance in ever-decreasing packages.

Intel and IBM presented technical papers outlining their latest desktop processors built on 90-nanometer process technology. The existing shift to 90-nanometer process technologies from the older 0.13-micron (130-nanometer) technologies jump has raised concerns about current leakage, and the topic was a significant part of both companies' presentations.

As lines within chips decrease in size to average widths of 90 nanometers, more electrons are able to penetrate the thin walls and leak out of the processor as heat. Excessive amounts of heat can damage a system and, as chips get hotter, more expensive cooling equipment will be required to maintain performance.

About 30% of the total power consumed by Intel's latest Pentium 4 processor is wasted as current leakage, said Joseph Schutz, a vice-president in Intel's manufacturing group. This was within the power budget outlined by Intel designers for leakage, but without careful attention to the problem, the current leakage could have been much worse, he said.

IBM's 2.5GHz PowerPC 970FX will dissipate about 50 watts of power during typical use, down from 66 watts consumed by its PowerPC 970 predecessor at a lower clock speed, said Norman Rohrer, senior technical staff member at IBM.

IBM's chip will launch soon in an Apple Computer XServe system, and is expected to also power a version of Apple's PowerMac desktop.

Power consumption was also a concern for designers of IBM's Power 5 chip. That server processor consumes 160 watts of power at 1.8GHz and, while power consumption is less of a problem in the server world, IBM still implemented several architectural changes to save as much power as possible, said Joachim Clabes, design team leader for the Power 5.

IBM will release servers built with the dual-core Power 5 processor later this year. The chips will offer 20% to 40% improvements in performance over the older Power 4 generation partly because of the improved multithreading technology, Clabes said.

Fresh off a large product launch last week, Sun presented details on two chips that are slated for future products. The company has developed a dual-core UltraSparc processor for dense servers that will consume 23 watts of power at 1.2GHz.

Sun has also launched its first dual-core processor, the UltraSparc IV. The new chip will allow Sun to offer blade and small rack servers with high-performing 64-bit chips and Sun's Solaris operating system.

The company has also built samples of a 90-nanometer UltraSparc chip that will use a 4Mbyte Level 2 cache to boost performance. Adding a larger cache to a chip allows the CPU to store increased amounts of frequently accessed data in a repository closer to the processor than the main memory.

Sony also presented a paper on its work reducing frequency and power consumption in system designs for handheld devices, and Xelerated discussed a network processor capable of generating up to 40Gbytes per second of throughput.

Tom Krazit writes for IDG News Service

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