Unisys drops 88000 RISC effort, will stress Intel x86 CISC MPUs

Electronic News, Dec 23, 1991 by Gerry Khermouch

BLUE BELL, Pa. -- Unisys has scrapped its efforts to develop an 88000-based RISC platform for its Unix-based systems in favor of a closer alliance with Intel, whose x86-based CISC MPUs already are at the heart of most of its open-systems machines.

The Blue Bell company last week said it would standardize its open systems product lines on Intel's x86 MPU through a memorandum of understanding that calls for the two companies to work together to refine the Intel architecture for high-end, on-line transaction processing (OLTP) applications.

In essence Unisys is gambling that anticipated performance improvements in the x86 line, coupled with a multiprocessor-oriented software approach the company has been developing with French-based Chorus Systemes, will allow the company's Unix machines to approach, or even match, the performance levels expected for RISC-based systems used in commercial applications over the next several years.

"From our perspective, it unifies our direction," said Ron Bell, vice president and general manager of the Unix Systems group in San Jose. "Even if it appeared externally that our major effort was toward Intel and the U6000 line in particular, there was some effort in the RISC arena." That will now be dropped, he indicated.

That RISC effort was so subdued that Unisys did not even formally disclose the start of shipments this spring of its first 88000-based machine, which was targeted at Japan but was to enter the U.S. and European markets later this year (EN, May 13). It never did.

By some accounts, the tepid effort on the 88000 played a role in the departure this summer of its champion within Unisys, John Chen, who went to RISC vendor Pyramid Technology and was succeeded at Unisys by Mr. Bell (EN, Aug. 12). Mr. Bell, previously the group director of systems engineering for the Unix Systems group, was named Mr. Chen's interim successor, a promotion that was quietly made permanent last week.

In an interview, Mr. Bell acknowledged that the weak reception accorded by the market to Motorola's 88000 MPU had encouraged Unisys to explore what RISC alternatives might be available. After weighing the impact that a change would exert on time to market and other factors, the company concluded that it made more sense to stick with Intel -- particularly given the convergence that is expected between RISC and CISC performance levels in the next few years, Mr. Bell said.

"In the early 1980s through 1985, there were some real differentiators," Mr. Bell said. "As we look into the future, those architectural differences really blur," as CISC and RISC vendors both move toward single-cycle execution, superscalar architectures and out-of-order execution.

Mr. Bell acknowledged it is by no means certain that Intel will be able to climb an equivalent price/performance curve to RISC. However, for the "mission critical" commercial applications it is targeting, Unisys may be able to offset any sheer hardware advantages of RISC by the software approach it is taking in the multiprocessing arena through its two-year-old partnership with Chorus. The French-based firm has developed a microkernel implementation of Unix System V Release 4 that was recently endorsed by Unix Systems Laboratories (EN, Nov. 25).

"They've got stuff in the pipe that will get their Intel box into the same performance range" as RISC systems, said Brian Jeffery, managing director of International Technology Group, Los Altos, Calif. The Chorus-derived technology "lets you do fairly powerful multiprocessing stuff without a tightly coupled MP architecture," a more cumbersome approach that has been adopted by other systems vendors.

While the Chorus microkernel so far has only been employed in Unisys' 88000-based machine, Mr. Bell noted that "the effort that's gone on is pretty architecture-independent" and can be adapted to CISC.

Contacted last week, Mr. Chen maintained that the RISC instruction set was better suited to Chorus' distributed approach, but added that, with some work, the new approach should be at least viable.

"From my perspective, not enough effort was put into the 88000-based work," which called for a RISC-based high end and Intel-based low end linked by a distributed environment. But given the company's financial predicament. "There was not enough bandwidth at Unisys to cover" a two-track program.

Unisys' decision to make a whole-hearted commitment to the Intel architecture speels another blow to any hopes that Motorola, the developer of the 88000 RISC chip, may still harbor of building a broader user base for that MPU among major systems firms. The deal also will hasten the exit of Motorola's 68040 CISC chip from Unisys' product line, where it is still used in the S series of machines.

The deal also came amid several other developments that shed light on how Unisys is fine-tuning its approach to Unix hardware. A few days earlier, the company had disclosed its intention of shuttering a Flemington, N.J., personal computer operation; it also disclosed last week that it had renewed an OEM agreement with Sequent Computer Systems Inc., a maker of Intel-based multiprocessors, for another two years.