IBM unveiled two new PowerPC chips Thursday at an event in Tokyo, one month after its primary customer for those chips announced plans to switch to Intel's processors.

The new PowerPC 970MP is a dual-core version of the PowerPC 970FX, which users of Apple's Power Mac and iMac computers know as the G5 processor. IBM also unveiled a low-power version of the 970FX chip with power consumption statistics that would make it suitable for a notebook.

IBM had said little publicly about its PowerPC road map during the last several weeks of speculation, then confirmation, that Apple would make the historic switch away from the PowerPC architecture in favor of Intel's x86 architecture starting in 2006. IBM and Apple have had a rocky partnership since IBM became the exclusive supplier of the G5 processors. Manufacturing problems at IBM caused a delay in shipments of the G5 chips last year and power-consumption issues forced Apple to use liquid cooling in a high-end Power Mac and hold back on launching a G5 PowerBook or iBook.

In fact, Apple CEO Steve Jobs cited concern about IBM's long-term road map for high-performance processors with low power consumption when announcing the switch to Intel's chips last month. However, he also said that Apple planned to release new PowerPC-based Macs between now and the time the switch gets under way next year. Apple won't switch its entire lineup of Macs to Intel until 2007.

An Apple spokeswoman declined to comment on the company's plans for the new PowerPC chips.

The new low-power PowerPC 970FX chip will consume 13 watts of power when running at 1.4GHz and 16 watts of power running at 1.6GHz, under typical operating conditions, IBM said in a press release. It's difficult to compare the power consumption of this chip to Intel's low-power leader, the Pentium M, because Intel publishes thermal design guidelines for PC manufacturers while IBM cites "typical" power consumption.

Intel advises PC manufacturers to design Pentium M-based PCs that can handle 27 watts of power consumption, according to Intel technical documents. The company also has lower-power versions of the Pentium M that run at slower clock speeds.

Likewise, it's impossible to compare processor performance, especially processors using different architectures, without independent testing. But the power-consumption figures of the new 970FX chips would allow Apple to design a G5-based notebook that would probably outperform the company's current crop of G4-based iBooks and PowerBooks.

The new dual-core PowerPC 970MP chips bring IBM in line with the rest of the PC processor industry, which is shifting to dual-core designs in order to improve performance. IBM was the first company to ship a dual-core server processor back in 2001, but Intel and AMD have released dual-core chips for desktop PCs this year.

Each 970MP core uses a dedicated bank of 1MB of Level 2 cache, giving each core twice the Level 2 cache of the entire 970FX chip, IBM said. Power-saving characteristics built into the chip allow it to alter the power consumption of each core as processing requirements allow, even to the point of shutting down one core if it isn't needed, the company said. The chip can be used at clock speeds ranging from 1.4GHz to 2.5GHz.

An IBM spokesman was unable to comment on the availability of the new chips, as the appropriate IBM executives and spokespeople were in Tokyo for the event. IBM did not mention Apple or even the PC industry in its press release, targeting the 970MP for entry-level servers and both chips for embedded applications.