A processor in the hand ..

Fast PowerPC processors: Gotta love 'em.

Not surprisingly, speed was big news at this week's IEEE International Solid State Circuit Conference in San Francisco (see http://www.macweek.com/mw_1206/nw_ibmmotorola.html). In addition, sources said, progress is being made on some slick new features for G4, the next generation of the PowerPC architecture. But Mac fans need to exercise some caution: The leap from seemingly miraculous technology demos to shipping products is a long one.

At the San Francisco meeting, engineers from IBM Microelectronics Division presented papers on several new high-performance PowerPC chips, including one that will run at 1,100 MHz, or 1.1 gigahertz. The demonstration architecture was a prototype, specially created to show the world that the PowerPC RISC architecture still has the right stuff. Company representatives were quick to point out, however, that this chip was a skunkworks project and nothing that will land in a workstation or Mac any time soon.

Prototype or not, I was impressed by the gigahertz speed, especially since it was the result of tweaks to the current RISC architecture. Contrary to several reports, the chip didn't rely on the hot new copper-process manufacturing technology IBM announced last summer. Instead, it used the same process developed for the faster varieties of the PowerPC 603e and 604e, such as the 300-MHz version code-named Mach 5.

(Note to silicon mavens: The news release for the gigahertz technology is at http://www.research.ibm.com/news/detail/1000mhz.html. The site has several photographs of the chip wafer, including one displayed by Mark Dean, IBM fellow and director of the company's Austin Research Lab, where the gigahertz design was engineered. There's also a layout diagram of the processor showing the placement of each logical element.)

Overshadowed by the super-fast processor was a 480-MHz PowerPC G3 that was, in fact, created with the copper process. Although the PowerPC camp was quick to point out that the 480-MHz chip isn't an announced product, it is the first solid evidence of the copper-based chips expected to reach the market by the end of the year.

So what's the difference? The gigahertz demonstration proves what can be done with PowerPC, but chips of this speed will have a long journey to market. Furthermore, just because the chip carries the PowerPC moniker doesn't mean vendors will be able to use it in a Mac.

The PowerPC label describes a broad RISC architecture comprising different families of processors, each with different capabilities. Some are designed for servers or Unix workstations; others, like the 750, are optimized for the requirements of content-rich Mac applications.

In contrast to the gigahertz prototype, the demonstration of the 480-MHz G3 shows what is being done now for forthcoming versions of a shipping product line. It isn't a finished product like the current 300-MHz G3s; rather, it gives us a taste of future performance.

While the high-speed processors went through their paces in San Francisco, sources provided additional details about the new capabilities that will be available for the PowerPC G4. They said work continues on multiprocessing and VMX (Video and Multimedia Extensions) enhancements to the PowerPC architecture.

While Apple will make the choice of which schemes it will introduce to the Mac platform, and when, sources pointed out that G4 technologies will also have a life outside the desktop computer market. The PowerPC alliance reportedly expects to sell chips with integrated MP and digital-signal processing capabilities to vendors of embedded applications, such as souped-up switches for telecommunications and other needs for low-power, high-speed processors. This market will boost volumes of the chips and help keep the PowerPC vital.

The great medieval rabbi Maimonides (1135-1204) offered a thought: "A miracle cannot prove that which is impossible; it is useful only as a confirmation of what is possible." A technology demonstration of a chip running at 1.1 gigahertz is great, almost miraculous news for the long term. The same is true for the future G4 technologies. However, the performance gains that really should matter to users are already being made in current G3 systems and the reportedly zippy models due to arrive over the next half year.

Executive Editor/News David Morgenstern welcomes feedback at (david_morgenstern@macweek.com).