IBM announces 1GHz G3

IBM announced the 750FX PowerPC processor today at the Microprocessor Forum in San Jose. The Processor will run between 700MHz and 1GHz, and will have a 512KB on-die L2 cache. As MacCentral predicted on Friday, the 750FX will use IBM’s most advanced manufacturing process — a 0.13-Micron copper process with SOI (Silicon On Insulator) and SiLK low-K dielectric. The new processor will begin sampling in January and will ship in volume shortly thereafter. “This is our highest performing PowerPC product,” Dean Parker, Manager of PowerPC marketing at IBM, told MacCentral.

The 750FX is an upgrade to the current G3 line. Earlier versions of the 750 include the IBM 750CX and 750CXe, which are used in Apple’s iMac and iBook systems. “We developed the 750FX to provide easy upgrades for our G3 customers and to use our most advanced manufacturing technology in the G3 line,” said Parker.

The overall goal of the 750FX is to optimize system performance. In addition to doubling the L2 cache size to 512KB from the 750CX’s and 750CXe’s L2 cache size of 256KB, IBM also doubled the peak system bus speed to 200MHz. IBM and two of its partner developers, Tundra Semiconductor and Marvell Technologies, are developing controller chips to take advantage of the faster bus. In addition to making the bus faster, IBM has also improved the bus efficiency to provide 25 percent greater bandwidth.

The 750FX showcases IBM’s latest manufacturing technology improvements, and is the first volume product to do so. This is the first PowerPC to use SOI and a low-K dielectric compound in tandem to increase performance and reduce power consumption. SOI reduces power consumption and improves efficiency by allowing the gates of the processor to close more quickly and with less power. Low-K dielectric further reduces power consumption and further boosts efficiency by preventing nearby copper wires from interfering with each other electrically. IBM’s low-K dielectric compound on the 750FX is SiLK — a brand name for the compound that is manufactured by Dow Chemical.

SOI and SiLK taken together with IBM’s smallest 0.13-micron copper manufacturing process has resulted in a processor that typically dissipates 3.6W of power at 800MHz — substantially lower than other similarly rated processors. The smaller manufacturing process also allows for a larger cache on a very small die — 34.6 square millimeters for 39 million transistors.

Parker told MacCentral that the 750FX has been designed for all of those markets that currently use G3s. This includes embedded markets, desktop markets, networking and all other areas where the PowerPC is used. Parker was also quick to point out that he 750FX does not have a SIMD (Single Instruction Multiple Data) execution unit like the G4’s AltiVec, as has been previously speculated elsewhere.

Parker would not comment about whether IBM would consider adding this feature to future products. “I cannot add details to our processor roadmap,” said Parker, “however, the roadmap provides an excellent sense of direction, and IBM is still developing products within the guidelines of the roadmap.”