The Am486 is a 80486-class family of

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

processors A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, ...

that was produced by

AMD Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufactur ...

in the 1990s.

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...

beat AMD to market by nearly four years, but AMD priced its 40 MHz 486 at or below Intel's price for a 33 MHz chip, offering about 20% better performance for the same price. While competing 486 chips, such as those from

Cyrix Cyrix Corporation was a microprocessor developer that was founded in 1988 in Richardson, Texas, as a specialist supplier of floating point units for 286 and 386 microprocessors. The company was founded by Tom Brightman and Jerry Rogers. In 19 ...

, benchmarked lower than the equivalent Intel chip, AMD's 486 matched Intel's performance on a clock-for-clock basis. While the

Am386 The Am386 central processing unit, CPU is a IBM PC compatible, 100%-compatible clone of the Intel 80386 design released by AMD in March 1991. It sold millions of units, positioning Advanced Micro Devices, AMD as a legitimate competitor to Intel Co ...

was primarily used by small computer manufacturers, the Am486DX, DX2, and SX2 chips gained acceptance among larger computer manufacturers, especially Acer and

Compaq Compaq Computer Corporation (sometimes abbreviated to CQ prior to a 2007 rebranding) was an American information technology company founded in 1982 that developed, sold, and supported computers and related products and services. Compaq produced ...

, in the 1994 time frame. AMD's higher clocked 486 chips provided superior performance to many of the early

Pentium Pentium is a brand used for a series of x86 architecture-compatible microprocessors produced by Intel. The original Pentium processor from which the brand took its name was first released on March 22, 1993. After that, the Pentium II and Pe ...

chips, especially the 60 and 66 MHz launch products. While equivalent

Intel 80486DX4 IntelDX4 is a clock-tripled i486 microprocessor with 16-kB Level 1 cache.http://www.pld.ttu.ee/~prj/486dev.pdf Intel named it DX4 (rather than ''DX3'') as a consequence of litigation with AMD over trademarks. The product was officially n ...

chips were priced high and required a minor socket modification, AMD priced low. Intel's DX4 chips initially had twice the cache of the AMD chips, giving them a slight performance edge, but AMD's DX4-100 usually cost less than Intel's DX2-66. The enhanced Am486 series supported new features like extended power-saving modes and an 8

KiB The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

Write-Back In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhe ...

L1-Cache, later versions even got an upgrade to 16 KiB Write-Back L1-Cache. The 133 MHz AMD

Am5x86 The Am5x86 processor is an x86-compatible CPU announced in November of 1995 by AMD for use in 486-class computer systems. It began shipping in December of 1995, with a base price of $93 per unit in bulk quantities. Before being released, it wa ...

was a higher clocked enhanced Am486. One derivative of the Am486 family is the core used in the

AMD Élan Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufactu ...

SC4xx family of microcontrollers marketed by AMD AMD has produced

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that memorialize the Am486SX2-66.

Features

CPU features table

Am486 models

WT = Write-Through cache strategy, WB = Write-Back cache strategy

References

External links

AMD: Enhanced Am486 Microprocessors

cpu-collection.de
AMD Am486 processor images and descriptions {{AMD_processors

Am486 The Am486 is a 80486-class family of computer processors that was produced by AMD in the 1990s. Intel beat AMD to market by nearly four years, but AMD priced its 40 MHz 486 at or below Intel's price for a 33 MHz chip, offering abo ...