Am486

AMD Am486 Microprocessor

The Am486 was a 80486-class family of computer processors that were 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 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.

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.

AMD's higher clocked 486 chips, provided superior performance to many of the early Pentium chips, especially the 60 and 66 MHz launch products. While equivalent Intel 80486DX4 chips were priced high and required a minor socket modification, AMD priced low. Intel's DX4 chips 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 133MHz AMD Am5x86 was an enhanced Am486.

	Introduced
Am486 DX-40	40 MHz	April 1993
Am486 DX2-50	50 MHz	April 1993
Am486 DX2-66	66 MHz
Am486 SX2-66	66 MHz	1994
Am486 DX2-80	80 MHz
Am486 DX4-90	90 MHz
Am486 DX4-100	100 MHz	1993
Am486 DX4-120	120 MHz

External links

*AMD: Enhanced Am486® Microprocessors
*AMD: 30 Years of Pursuing the Leader. Part 2
*cpu-collection.de AMD Am486 processor images and descriptions