Uploaded September 2022 | Updated September 2026, 4 hours ago
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. Probably one of the most well-known microprocessor bugs in the IT industry is the Pentium floating-point division bug that gained widespread attention in 1994.
A replacement for the socket 3 systems using 80486 processors, Intel developed a new socket 4 chip based on the P5 microarchitecture and named it Pentium introducing it in 1993. It ran at a 60MHz clock speed (including a 66MHz version later on) using a new floating-point calculation methodology and still utilized a 5v power interface like the 486. It was distinguishable by the gold top heat spreader. During manufacturing the etching machine lacked or did not have the correct data for etching an array utilized by the FPU leaving it empty or with zeroes. This problem would make its way into later Pentiums using the P54C architecture (noted by their dark ceramic heat spreaders) that ran at 75, 90 and 100 megahertz. By the time of the introduction of the P54CQS and subsequent architectures the bug had been corrected.
In 1994 Thomas Nicely, a professor of mathematics at Lynchburg College in Virginia (now the University of Lynchburg) discovered the presence of the bug while performing arithmetic operations involving long divisions on affected systems. He noted that results from older 486-based systems and Pentium-clones were providing the correct values but the Pentium ones were returning incorrect results. In response Nicely developed a small test program named PENTBUG and reached out to other individuals including tech professionals to evaluate their Pentium systems for the presence of the bug. He'd be proven correct as others would soon discover the presence of the bug on their Pentium systems and the issue became known worldwide.
Intel did acknowledge the presence of the bug but their initial response was the bug being too insignificant for the typical user to be concerned with. This did not go over well and soon Intel began a voluntary recall of all affected Pentium processors in December of 1994. Subsequently the discovery of the bug and the widespread media attention it gained proved negative for Intel. Their stock price fell, computer manufacturers particularly IBM stopped producing machines using Pentium processors, tainted reputation with consumers and a several hundred-million dollar loss in business for that tax year.
Checking for the presence of the bug on an affected system is fairly easy. Using an arithmetic program that is old enough to utilize the FPU without any software correction a user divides 4195835 by 3145727. If the result given is 1.333739 then the processor has the bug. The correct value is 1.333820.
#intel #bug #processor
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Visit my Linktree to access my socials and other channels: https://linktr.ee/mausolfb
-----------------------------------------------------------
. Probably one of the most well-known microprocessor bugs in the IT industry is the Pentium floating-point division bug that gained widespread attention in 1994.
A replacement for the socket 3 systems using 80486 processors, Intel developed a new socket 4 chip based on the P5 microarchitecture and named it Pentium introducing it in 1993. It ran at a 60MHz clock speed (including a 66MHz version later on) using a new floating-point calculation methodology and still utilized a 5v power interface like the 486. It was distinguishable by the gold top heat spreader. During manufacturing the etching machine lacked or did not have the correct data for etching an array utilized by the FPU leaving it empty or with zeroes. This problem would make its way into later Pentiums using the P54C architecture (noted by their dark ceramic heat spreaders) that ran at 75, 90 and 100 megahertz. By the time of the introduction of the P54CQS and subsequent architectures the bug had been corrected.
In 1994 Thomas Nicely, a professor of mathematics at Lynchburg College in Virginia (now the University of Lynchburg) discovered the presence of the bug while performing arithmetic operations involving long divisions on affected systems. He noted that results from older 486-based systems and Pentium-clones were providing the correct values but the Pentium ones were returning incorrect results. In response Nicely developed a small test program named PENTBUG and reached out to other individuals including tech professionals to evaluate their Pentium systems for the presence of the bug. He'd be proven correct as others would soon discover the presence of the bug on their Pentium systems and the issue became known worldwide.
Intel did acknowledge the presence of the bug but their initial response was the bug being too insignificant for the typical user to be concerned with. This did not go over well and soon Intel began a voluntary recall of all affected Pentium processors in December of 1994. Subsequently the discovery of the bug and the widespread media attention it gained proved negative for Intel. Their stock price fell, computer manufacturers particularly IBM stopped producing machines using Pentium processors, tainted reputation with consumers and a several hundred-million dollar loss in business for that tax year.
Checking for the presence of the bug on an affected system is fairly easy. Using an arithmetic program that is old enough to utilize the FPU without any software correction a user divides 4195835 by 3145727. If the result given is 1.333739 then the processor has the bug. The correct value is 1.333820.
#intel #bug #processor
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