To ALL: Article...No recall of Pentium2 and Pentium Pro!....
news.com
Intel posts bug explanation
By Brooke Crothers
May 9, 1997, 3 p.m. PT
Intel (INTC) has posted an explanation to a widely reported bug in its Pentium Pro and Pentium II processors today, stating that the glitch could generate wrong answers in some cases.
The fact that a wrong answer can result is potentially more serious than the glitch as first stated publicly by Robert Collins on his Web site Intel Secrets. Collins went no further, essentially, than asserting that a data "overflow" condition could occur which could then possibly crash a system.
Intel has stated clearly that it will not issue a recall of the Pentium II or Pentium Pro processors but, instead, has described some software work-arounds at Workaround.
The flaw was depicted initially by engineer Robert Collins. Intel's explanation is now posted at Intel.
Intel is reacting much differently to the problem this time than it did a few years back when a professor at Lynchburg College in Virginia discovered a bug in the Pentium processor. Intel, at that time, was adamant in asserting that the bug was minor or inconsequential. This time Intel will step out of the way and leave it to software and hardware companies to define the seriousness of the problem.
The problem can occur when very large "floating point" numbers are converted into "integer" numbers, something which occurs in software programs.
"The conversion of floating-point numbers to integer [numbers] is required by some applications. However, some of them may be too large [to convert properly]" in some cases, Intel said.
"Erroneous results [can occur] when the [number] is so large that it will not fit into the target data size," Intel said in its technical evaluation of the problem.
The fact that erroneous results are generated supports a claim by Martin Atkinson-Barr, a physicist who works as a computer consultant and writes software programs, that the problem is more serious than originally characterized by Collins.
The glitch, as stated earlier this week by Atkinson-Barr, can "propogate" invalid data resulting in a wrong answer, an Intel spokesperson confirmed.
"As a result of our investigation, we have concluded that, as is our normal practice, we will include the fix for this errata along with other errata into future [processor revisions]," Intel stated in the posting.
"We have been working with industry software developers...to determine if their software applications would be affected by the [bug]. We will ...work with software manufacturers as needed to integrate work-arounds into their future product releases," the company added.
Software and hardware developers also chimed in. "We have determined the erratum on the Pentium Pro and Pentium II processors will not affect CorelDRAW 7," said Cathy Wright, director of software development for Corel's Graphics line.
"IBM is working closely with Intel to analyze the problem and the potential impact on IBM software. Our analysis and testing on several major IBM software offerings has shown this software to be unaffected by this issue," IBM said.
NEWS.COM first reported the flaw on May 2, stating that Collins had discovered a "major" floating-point bug in the Pentium Pro and Pentium II processors.
Atkinson-Barr said "programs that have [numbers] with values that fall within the bug range and make an attempt to convert them...will give the wrong answer and will not report any error. Fortran, C, Pascal, Algol--anything written in such a language--would be prone to this bug."
Collins had reported that the bug is not "computational" but related to a data "overflow" problem, a glitch that could cause a system to crash but wouldn't give a wrong answer pretending to be a right answer.
Based on one of the points made by Atkinson-Barr, Collins has now made a correction to his posting on the Intel Secrets Web site. "He was right. I changed it," Collins said.
The change is now highlighted in red in a section of the report called "The Nature of the Bug." Collins has dubbed the Pentium Pro and Pentium II bug the Dan-0411 bug.
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Well, Well, now that the shorts have made a couple of bucks it's time for Intel to resume it's relentless climb upward.
Michael |
