The Intel Pentium® Chip Case
In late 1994, the media began to report that there wasa flaw in the new Pentium microprocessor produced by Intel. Themicroprocessor is the heart of a personal computer and controls allof the operations and calculations that take place. A flaw in thePentium was especially significant, since it was the microprocessorused in 80% of the personal computers produced in the world at thattime.
Apparently, flaws in a complicated integrated circuitsuch as the Pentium, which at the time contained over one milliontransistors, are common. However, most of the flaws areundetectable by the user and don’t affect the operation of thecomputer. Many of these flaws are easily compensated for throughsoftware. The flaw that came to light in 1994 was different: It wasdetectable by the user. This particular flaw was in thefloating-point unit (FPU) and caused a wrong answer whendouble-precision arithmetic, a very common operation, wasperformed.
A standard test was widely published to determinewhether a user’s microprocessor was flawed. Using spreadsheetsoftware, the user was to take the number 4,195,835, multiply it by3,145,727, and then divide that result by 3,145,727. As we all knowfrom elementary math, when a number is multiplied and then dividedby the same number, the result should be the original number. Inthis example, the result should be 4,195,835. However, with theflawed FPU, the result of this calculation was 4,195,579[Infoworld, 1994]. Depending on the application, thissix-thousandths-of-a-percent error might be very significant.
At first, Intel’s response to these reports was todeny that there was any problem with the chip. When it became clearthat this assertion was not accurate, Intel switched its policy andstated that although there was indeed a defect in the chip, it wasinsignificant and the vast majority of users would never evennotice it. The chip would be replaced for free only for users whocould demonstrate that they needed an unflawed version of the chip[Infoworld, 1994]. There is some logic to this policy from Intel’spoint of view, since over two million computers had already beensold with the defective chip.
Of course, this approach didn’t satisfy most Pentiumowners. After all, how can you predict whether you will have afuture application where this flaw might be significant? IBM, amajor Pentium user, canceled the sales of all IBM computerscontaining the flawed chip. Finally, after much negative publicityin the popular personal computer literature and an outcry fromPentium users, Intel agreed to replace the flawed chip with anunflawed version for any customer who asked to have itreplaced.
It should be noted that long before news of the flawsurfaced in the popular press, Intel was aware of the problem andhad already corrected it on subsequent versions. It did, however,continue to sell the flawed version and, based on its earlyinsistence that the flaw did not present a significant problem tousers, seemingly planned to do so until the new version wasavailable and the stocks of the flawed one were exhausted.Eventually, the damage caused by this case was fixed as the mediareports of the problem died down and as customers were able to getunflawed chips into their computers. Ultimately, Intel had awrite-off of 475 million dollars to solve this problem.
What did Intel learn from this experience? The earlydesigns for new chips continue to have flaws, and sometimes theseflaws are not detected until the product is already in use byconsumers. However, Intel’s approach to these problems has changed.It now seems to feel that problems need to be fixed immediately. Inaddition, the decision is now based on the consumer’s perception ofthe significance of the flaw, rather than on Intel’s opinion of itssignificance.
Indeed, similar flaws were found in 1997 in the earlyversions of the Pentium II and Pentium Pro processors. This time,Intel immediately confirmed that the flaw existed and offeredcustomers software that would correct it. Other companies also seemto have benefited from Intel’s experience. For example, Intuit, aleading manufacturer of tax preparation and financial software,called a news conference in March of 1995 to apologize for flaws inits TurboTax software that had become apparent earlier in thatyear. In addition to the apology, they offered consumersreplacements for the defective software.
