Lessons Learned: Pentium Flaws Aid Intel In Sandy Bridge Chipset Recall


Intel is receiving mostly positive feedback for its handling of the Sandy Bridge chipset recall, and a big reason for that may be the chip maker's past missteps in dealing with high-profile design errors and recalls.

The world's largest chip maker was once known for making critical mistakes related to product flaws, and one episode in particular 17 years ago proved to be a crucial learning experience for Intel that helped it avoid a potentially embarrassing repeat.

In 1994, a few missing entries in Intel's lookup table for its divide operation algorithm led to an error in the P5 Pentium's floating point unit, producing inaccurate results in approximately 1 in 9 billion floating point divides. Intel referred to it as a "slight reduction in precision." That's a long way of saying that the chips would occasionally cause incorrect math results in very rare cases.

At first, Intel appeared to ignore the problem and downplay the significance of the error. Later, the company offered to replace processors -- but for only those Pentium users who could prove that their systems had been affected by the FDIV flaw. In other words, simply having the flawed product wasn't enough to get you a refund; you had to have the product break before getting your money back. Imagine Ford and Firestone requiring customers to actually crash their Explorers before recalling the vehicles.

Predictably, Intel's reaction to the floating point error triggered a public outcry that quickly built momentum. Eventually, the chip giant offered to replace all flawed Pentium processors based on request and cover the costs associated with its Pentium FDIV replacement program.

On Jan. 31st, just a few weeks after launching the much-anticipated Sandy Bridge platform at CES 2011 in Las Vegas, Intel announced a design error in its Cougar Point chipset, affecting its Core i5 and i7 Sandy Bridge processors. Intel said it had learned -- after the chipsets began shipping -- that Cougar Point's SATA ports would degrade over time, adversely affecting SATA hard drives in some Sandy Bridge systems.

According to Intel Chief Financial Officer Stacy Smith, all Intel needed to do to fix it was make a change to a metal layer in the SATA ports. Smith said Intel's engineers identified the problem, corrected it, and began production on replacement chipsets all within a matter of days.

Tim Ulmen, principal at Midwest IT Solutions Group, a Wichita, Kan.-based system builder, said the Cougar Point issue is reminiscent of the Intel Pentium FDIV bug from 1994.

"Albeit the error occurred rarely, it was a design flaw and for a brief period of time Intel skirted the issue and set a policy of replacing CPUs only in cases where the customer could prove the flaw affected them," Ulmen said. "I can vividly remember those days as I was involved with selling tier one computers at a retail level. Most of my customers tended to discount the error because of its infrequent nature but I did have some customers who insisted on a replacement CPU."

Meanwhile, Todd Swank, vice president of marketing at system builder Nor-Tech, said he recalls the Pentium FDIV error being a major issue -- but one that's very different from the Sandy Bridge situation.

"[The Pentium FDIV flaw] happened after so many customers had already had systems in hand and were already relying on them," Swank said. "Plus, that was a difficult problem to detect and customers feared that their fundamental data could be flawed and they didn’t even know about it," Swank said. "The recent Sandy Bridge episode was caught so early that very few customers were actually affected. It also involved a very obvious failure should a customer’s SATA drive suddenly stop working, nothing as subtle as the original Pentium flaw."

Next: The Pentium FDIV Bug