Autor: Jerzy Pastusiak (pastupam_at_uoo.univ.szczecin.pl)
Data: Sat 26 Nov 1994 - 16:04:56 MET
Poniewaz sprawa Pentium budzi pewne zainteresowanie na liscie POLIP, pozwalam
sobie przeslac zainteresowanym artykul z the New York Times. Mam caly czas
skrupuly, ze przesylam to na POLIPa, ale z drugiej strony jestem na liscie
prawie dwa tygodnie i czytalem wiele listow, wiec mam nadzieje, ze zawarta
informacja sie komus przyda.
Jezeli ktos ma watpliwosci do czego Amerykanie uzywaja P90, moze zapisac sie
na CDROM-L chociaz na kilka dni. Przy czym uprzedzam, ze bedzie mial
300 kBy listow/dzien, czyli prawie 3 razy wiecej niz z POLIPa.
Z mojego doswiadczenia wynika, ze niestety P90, jest procesorem, ktory w od-
powiednim otoczeniu sprzetowym moze zapewnic wlasciwa prace z Windowsami.
Jest prawdziwe, wedlug mnie powiedzenie, ze jezeli chce sie zrobic z P90 i088
nalezy zainstalowac Windowsy. Oczywiscie mozna miec uprzedzenia do Ww, ja je
mialem od poczatku, ale jak wiemy 98% mezczyzn ma uprzedzenia do kobiet.
My uzywamy P90 do obliczen SASem - pakiet statystyczny, sensowne minimum,
sam program zajmuje 90 MBy na dysku, tanie rozwiazanie.
Wybaczcie ze wielu zdan nie koncze, ale uwazam, ze czytaja ludzie inteligentni.
Przesylam serdeczne pozdrowienia ze Szczecina,
pogrozki, obelgi itp. uprzejmie prosze przesylac na moj adres,
oszczedzmy je stu innym z LISTY,
Jerzy Pastusiak, Szczecin, pastupam_at_uoo.univ.szczecin.pl .
>
> Newsgroups: comp.sys.intel
> Subject: Full Text of NYT Pentium Article
> Date: 24 Nov 1994 14:10:16 -0500
> Organization: America Online, Inc. (1-800-827-6364)
> Lines: 148
> Sender: news_at_newsbf01.news.aol.com
> Message-ID: <3b2oeo$nnr_at_newsbf01.news.aol.com>
> NNTP-Posting-Host: newsbf01.news.aol.com
>
> What follows is the full text of today's (11/24) New York Times article on
> the bug in the Pentium chip:
>
> 11/24:CIRCUIT FLAW CAUSES PENTIUM CHIP TO MISCALCULATE, INTEL ADMITS
>
> By JOHN MARKOFF
>
> c.1994 N.Y. Times News Service
>
> SAN FRANCISCO - An elusive circuitry error is causing a chip used in
> millions of computers to generate inaccurate results in certain rare
> cases, heightening anxiety among many scientists and engineers who rely on
> their machines for precise calculations.
>
> The flaw, an error in division, has been found in the Pentium, the current
> top microprocessor from Intel Corp., the world's largest chip maker. The
> chip, in several different configurations, is used in many computers sold
> for home and business use, including those made by IBM, Compaq, Dell,
> Gateway 2000 and others.
>
> The flaw appears in all Pentium chips now on the market, in certain types
> of division problems involving more than five significant digits, a
> mathematical term that can include numbers before and after a decimal
> point.
>
> Intel declined to say how many Pentium chips it made or sold, but
> Dataquest, a market research company in San Jose, Calif., estimated that
> in 1994 Intel would sell about six million Pentiums, roughly 10 percent of
> the number of personal computers sold worldwide.
>
> Intel said Wednesday that it did not believe the chip needed to be
> recalled, asserting that the typical user would have but one chance in
> more than nine billion of encountering an inaccurate result as a
> consequence of the error, and thus there was no noticeable consequence to
> users of business or home computers. Indeed, the company said it was
> continuing to send computer makers Pentium chips built before the problem
> was detected.
>
> William Kahan of the University of California at Berkeley, one of the
> nation's experts on computer mathematics, expressed skepticism about
> Intel's claims that the error would only occur in extremely rare
> instances.
>
> "These kinds of statistics have to cause some wonderment," he said. "They
> are based on assertions about the probability of events whose probability
> we don't know."
>
> At Jet Propulsion Laboratory in Pasadena, Calif., one satellite
> communications researcher who learned of the error this week said six
> Pentium machines were used in his group and their use had been suspended
> for now.
>
> "The Pentium appeared as a cost-effective means to do the kind of
> analytical computing that scientists and engineers do," said David Bell,
> the researcher. "But when we hear and see that there are problems, that
> puts a question mark on the results."
>
> A number of other computer scientists and engineers said the probability
> of encountering the problem would vary wildly depending upon what software
> the computer was using.
>
> In addition to its growing role in PCs, the Pentium chip is used in a
> number of larger computers that harness individual chips to work in
> tandem, creating supercomputer power. This technique, known as parallel
> processing, is used for weather forecasting, the aerodynamic simulation
> used in automotive and airplane design and in molecular engineering.
>
> Intel said the problem came to its attention in June and was corrected
> then, at the design stage. That change took some time to make its way
> through the chip production process, and Intel has only recently begun
> providing its largest customers with the revised chips, the company said.
>
> Intel acknowledged that the flaw could affect certain scientific and
> engineering applications in rare cases. Stephen L. Smith, the company's
> engineering manager for the Pentium, said discussions were under way with
> scientists and engineers.
>
> "Those are exactly the people who should call us," he said. "We're willing
> to work with them and understand what applications they are using that
> might be affected."
>
> For Intel, which has spent millions of dollars on an advertising campaign
> using the slogan "Intel Inside," the news of the defect might create
> something of a public relations problem.
>
> In recent months Intel has had success in positioning the Pentium as a
> chip for scientific and engineering applications, boasting that at a lower
> cost it matches the speed of rival processors made by Digital Equipment,
> Hewlett-Packard, IBM and Sun Microsystems.
>
> "The issue is being sure that the arithmetic is right," said Cleve Moler,
> chairman and chief scientist of the Mathworks, a software company in
> Natick, Mass., that develops mathematical software. "There are enough
> other things that can go wrong that I don't want to think about
> arithmetic."
>
> The Pentium flaw is not the first to be found in microprocessors. Both
> Intel's 386 and 486 chips, predecessors of the Pentium that remain in wide
> use, have had different math errors that were corrected when they were
> discovered. And in 1991 Sun Microsystems acknowledged that a division
> error in its Sparc work stations created a security loophole. That problem
> was later corrected.
>
> Some computer users said they believed that Intel had not acted quickly
> enough after discovering the error.
>
> "Intel has known about this since the summer; why didn't they tell
> anyone?" said Andrew Schulman, the author of a series of technical books
> on PCs. "It's a hot issue, and I don't think they've handled this well."
>
> The company said that after it discovered the problem this summer, it ran
> months of simulations of different applications, with the help of outside
> experts, to determine whether the problem was serious.
>
> The Pentium error occurs in a portion of the chip known as the floating
> point unit, which is used for extremely precise computations. In rare
> cases, the error shows up in the result of a division operation.
>
> Intel said the error occurred because of an omission in the translation of
> a formula into computer hardware. It was corrected by adding several dozen
> transistors to the chip.
>
> The error was made public earlier this month after Thomas Nicely, a
> mathematics professor at Lynchburg College in Lynchburg, Va., sent a
> private electronic-mail message to several colleagues, asking them to
> check their machines for the error.
>
> Nicely was calculating a series of reciprocals of prime numbers, in part
> to show that PCs now had enough power to be used instead of supercomputers
> for computationally intensive tasks.
>
> Nicely, who is now consulting with Intel, said he had run more than one
> quadrillion calculations on a revised Pentium chip and had not reproduced
> the error.
>
> After the Pentium flaw was made public, Intel began telling users that it
> had discovered and corrected the flaw in June, and last week it quietly
> began offering replacement chips to users concerned about the error.
>
> Executives at Compaq Computer Corp. and Dell Computer Corp., two large
> Pentium customers, said they had begun to receive calls from users who had
> found the error using a test recommended by Nicely.
>
> A spokeswoman for Compaq said the company was referring the calls to
> Intel. A spokesman for Dell said the company had been contacted recently
> by Intel and was dealing directly with customers.
>
>
>
>
> ----------------------------------------
> ----------------- Karsten M. Self selfka_at_hccompare.com 916.374.3844
> / / Analytic Consulting Dept / HealthCare COMPARE Corp
> / / 750 Riverpoint Drive, West Sacra
> ------------------
> Ed Self's Corollary to Atkinson's Law (thanks, Pop):
> Data corrupts. Absolute data corrupts absolutely.
>
>
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