Antares: PowerPC 970MP to pack dual cores for future Apple hardware

By Nick dePlume, Publisher and Editor in Chief
July 23, 2004 - Although Apple has only this year begun shipping G5 Power Macs and Xserves with the PowerPC 970FX processor, IBM plans to raise the bar with the chip's successor, a dual-core processor code-named "Antares," well-placed sources told Think Secret.





Known officially as the PowerPC 970MP, the chip will feature two interconnected microprocessors on a single 13.225mm x 11.629mm die -- a first for the 970 processor family. Each core will have its own 1MB L2 cache, sources said; the 970FX has only 512KB. L3 cache will not be supported.

The 970MP will feature a copper bus with 10 layers of metal; the dual cores will share a single Elastic Interface (EI) bus supporting a wide range of bus ratios and opening the door for higher bus speeds.

Antares will be manufactured using IBM's CMOS SOI10K process with Silicon on Insulator technology, sources said. The new chip will also support the VMX instruction set with Altivec-compatible Vector/SIMD units -- one on each core.

Aside from cache and bus improvements, Antares will boast a number of other design strides over the "Altair" 970FX chip. One area will be power management; the 970MP will feature enhancements to IBM's PowerTune technology -- first introduced in the 970FX -- which conserves power by throttling its clock speed on a dime. Both cores will throttle clock speeds and voltage up or down in tandem, sources said.

Antares will also feature a programmable ABIST diagnostic -- "array built-in self-test" -- that's designed with the Silicon on Insulator arrays in mind.

Sources confirmed that Apple is signed up to use the 970MP in future hardware products, presumably the Power Mac and Xserve product lines. According to sources, IBM designed the 970MP for use in a variety of configurations, including desktops, workstations, servers, and four-way SMP environments.

IBM will reportedly deliver the first prototypes to Cupertino in August and is projected to wrap up its own testing and begin production in January; this timetable suggests that customers could see the new processor in Apple products sometime in 2005.

IBM's plans call for delivering a 970MP that clocks at 3GHz with a 1GHz EI bus, according to sources. When comparing two chips of similar clock speeds, however, multiple-core processors deliver improved performance. IBM's initial plans called for multiple cores in the first G5, the 64-bit PowerPC 970, aka GigaProcessor UltraLite (GPUL).

Antares would be the first dual-core GPUL chip in an industry where AMD and Intel last month both announced plans to bring dual-core chips to market. In a recent interview on eWEEK.com with 970FX designer Norman Rohrer from IBM, Rohrer would not confirm whether a dual-core chip was in the cards, but "he did say that a dual-core chip would remove some of the pressure to constantly push clock speeds higher."

Oh but it is.

"The IBM PowerPC 970MP RISC Microprocessor
 is a dual-core, 64-bit implementation of the IBM
 PowerPC ? family of reduced instruction set computer
 (RISC) microprocessors that are based on the PowerPC
 Architecture. This dual microprocessor, also called the
 PowerPC 970MP, includes a Vector/SIMD facility which
 supports high-bandwidth data processing and compute-intensive
 operations. The 970MP is also designed to
 support multiple system organizations, including desktop
 and low-end server applications, up through 4-way SMP
 configurations.
 Note: The IBM PowerPC 970MP incorporates two complete
 microprocessors on a single chip, along with some
 common logic to connect these microprocessors to a system."