IBM Faces Limited Risk Halting Pentium Sales

For most companies that sell the chip, it's `business as usual'

For weeks, mathematically inclined computer buffs have been plugging complicated division problems into computers based on Intel Corporation's Pentium microprocessor and coming up with wrong answers.

The resulting brouhaha has created a public-relations disaster for Intel. Throughout, the company has stressed that the errors are extremely rare. This week, IBM, in Armonk, N.Y. turned up the heat by suspending Pentium sales and suggesting that the chip's mistakes may be far more common than Intel has let on.

The controversy is partly a debate over mathematical probabilities. But in a larger sense, it is a reflection of the personal computer's (PC) changing role in society. Once a tool for the technically oriented, it is now a mainstream home-consumer device. ``We have moved from being ... a technology company to a consumer-technology company,'' says Howard High, spokesman for Intel in Santa Clara, Calif.

Computers make mistakes

The company was not prepared for consumers' reaction about something the industry has long taken for granted: Computers make mistakes.

``This is more of a verification error than a design error,'' says Justin Harlow, research-program manager at Semiconductor Research Corporation in Research Triangle Park, N.C. ``The problem is that this [design] has so many combinations of numbers that it's completely unfeasible to test them all.''

Thus, engineers have to develop mathematical abstractions to try to prove that the technology works at the same time they are testing the chips. In Pentium's case, some flaws slipped through.

Pentium is a microprocessor that handles the major activity in a PC. Within the chip is a floating-point unit that does the complex math. This summer, after performing some 2 trillion random division problems on the unit, Intel engineers uncovered the flaw. The company fixed the problem but kept mum about the glitch. ``We really did feel it was a rare occurrence,'' Mr. High says.

But the glitch came to light anyway. A professor at Lynchburg College in Lynchburg, Va., discovered the problem and made known his concerns on the Internet, a worldwide web of computer networks, where word quickly spread. By mid-November, Intel was in the thick of a public-relations disaster.

How bad is the glitch? Most users will never be affected because the faulty calculations involve large or extremely precise numbers. Even then, Intel claims the average spreadsheet user will only get a wrong answer once every 27,000 years.

IBM, however, says the average spreadsheet user could see an error once every 24 days. The difference of opinion: IBM assumed that users are likely to use some numbers more than others, and that their software makes an average 4.2 million division operations a day, not the 1,000 operations Intel projected.

In halting Pentium shipments, IBM faces limited risk. Its Pentium-based machines account for less than 10 percent of the company's PC sales. Other vendors suggest the company may have ulterior motives in bashing the Intel chip, since it hopes to sell a rival desktop microprocessor next year. Computer companies having far bigger sales of Pentium machines are, so far, sticking with Intel.

``It's business as usual,'' says Roger Rydell, spokesman for Dell Computer Corporation in Austin, Texas, which continues to sell Pentium machines. Gateway 2000, Packard Bell, and Compaq Computer Corporation in Houston also continue to sell machines with the chip.

Why all the brouhaha?

Intel has had similar problems in early versions of its previous two generation chips, the 386 and 486. The reason the company faces such a brouhaha this time, industry officials suggest, is that the PC has become a much more common consumer device. Intel has not helped matters with its huge branding campaign. Before the ``Intel Inside'' campaign, few PC buyers would have known or cared what brand microprocessor sat inside their machines.

``Intel has created a huge amount of awareness with the end user,'' says Katherin Dockerill, a spokeswoman for rival chipmaker Cyrix Corporation in Richardson, Texas. ``I bet they regret it today.''

Sales of Pentium-based PCs, meanwhile, show few signs of slowing. Cyrix and another chip-maker, Advanced Micro Devices of Sunnyvale, Calif., plan to start selling their own Pentium-class microprocessors next year.

Both welcome any publicity that might extend the life span of their venerable but hot-selling 486 chips.

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