The Am486 is a 80486-class family of computer processors that was produced by AMD in the 1990s. The Intel 486, otherwise known as the 80486 i486 or just 486 was the first tightly pipelined X86 design A computer is a Machine that manipulates data according to a list of instructions. The 1990s collectively refers to the years between and including 1990 and 1999 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 about 20% better performance for the same price. Early AMD 486 chips were drop-in replacements for their Intel counterparts, but later AMD clock-doubled 486s ran at 3. 3 volts instead of Intel's 5 volts, which limited their suitability as upgrade chips until third-party voltage adapters appeared on the market.
While competing 486 chips, such as those from Cyrix, benchmarked lower than the equivalent Intel chip, AMD's 486 matched Intel's performance on a clock-for-clock basis. Cyrix was a CPU manufacturer that began in 1978 in Richardson Texas as a specialist supplier of high-performance math co-processors for 286 and
While the Am386 was primarily used by small computer manufacturers, the Am486DX, DX2, and SX2 chips gained acceptance among larger computer manufacturers, especially Acer and Compaq, in the 1994 time frame. The Am386 CPU was released by AMD in 1991. A 100%-compatible clone of the Intel 80386 design it sold millions of units Acer Incorporated ( ( is a Taiwanese multinational electronics manufacturer Compaq Computer Corporation was an American Personal computer company founded in 1982 and is now a brand name of Hewlett-Packard. Year 1994 ( MCMXCIV) was a Common year starting on Saturday (link will display full 1994 Gregorian calendar)
AMD's higher clocked 486 chips, provided superior performance to many of the early Pentium chips, especially the 60 and 66 MHz launch products. The Pentium brand refers to Intel 's single-core x86 Microprocessor based on the P5 fifth-generation Microarchitecture. While equivalent Intel 80486DX4 chips were priced high and required a minor socket modification, AMD priced low. The Intel IntelDX4 is a clock-tripled i486 Microprocessor with 16kb L1 cache 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 Write-Back L1-Cache, later versions even got an upgrade to 16 KiB Write-Back L1-Cache.
The 133 MHz AMD Am5x86 was a higher clocked enhanced Am486. The Am5x86 processor is an X86 -compatible CPU introduced in 1995 by AMD for use in 486 -class Computer systems
Am486 models
| Model | Clock speed | VCore | L1-Cache | Introduced |
|---|---|---|---|---|
| Am486 DX-25 | 25 MHz | 5 V | 8 KiB WT | |
| Am486 DX-33 | 33 MHz | 5 V | 8 WT | |
| Am486 DX-40 | 40 MHz | 5 V | 8 WT | April 1993 |
| Am486 SX-33 | 33 MHz | 5 V | 8 WT | |
| Am486 SX-40 | 40 MHz | 5 V | 8 WT | |
| Am486 DE2-66 | 66 MHz | 3 V | 8 WT | 1996(?) |
| Am486 DX2-50 | 50 MHz | 5 V | 8 WT | April 1993 |
| Am486 DX2-66 | 66 MHz | 5/3. The clock rate is the fundamental rate in cycles per second (measured in Hertz) at which a Computer performs its most basic operations such as adding two The CPU core voltage ( VCORE) is the Power supply Voltage supplied to the CPU (which is a Digital circuit) GPU 3 V | 8 WT | |
| Am486 DX2-80 | 80 MHz | 5/3. 3 V | 8 WT | |
| Am486 SX2-50 | 50 MHz | 5 V | 8 WT | |
| Am486 SX2-66 | 66 MHz | 5 V | 8 WT | 1994 |
| Am486 DX4-75 | 75 MHz | 3. Year 1994 ( MCMXCIV) was a Common year starting on Saturday (link will display full 1994 Gregorian calendar) 3 V | 8 WT | |
| Am486 DX4-100 | 100 MHz | 3. 3 V | 8 WT | 1995 |
| Am486 DX4-120 | 120 MHz | 3. Year 1995 ( MCMXCV) was a Common year starting on Sunday. Events of 1995 3 V | 8 WT | |
| Enhanced Am486 DX2-66 | 66 MHz | 3. 3/3. 45 V | 8/16 WB | |
| Enhanced Am486 DX2-80 | 80 MHz | 3. 3/3. 45 V | 8 WB | |
| Enhanced Am486 DX4-75 | 75 MHz | 3. 3/3. 45 V | 8 WB | |
| Enhanced Am486 DX4-100 | 100 MHz | 3. 3/3. 45 V | 8/16 WB | |
| Enhanced Am486 DX4-120 | 120 MHz | 3. 3/3. 45 V | 8/16 WB |
WT = Write-Through cache strategy, WB = Write-Back cache strategy
External links
- AMD Am486 DE2 datasheet
- AMD: Enhanced Am486 Microprocessors
- AMD: 30 Years of Pursuing the Leader. Part 2
- cpu-collection.de AMD Am486 processor images and descriptions
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