- Am486
The Am486 is a
80486 -class family ofcomputer processors that was produced byAMD 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 andCompaq , 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 equivalentIntel 80486DX4 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 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.Am486 models
WT = Write-Through cache strategy, WB = Write-Back cache strategy
External links
* [http://www.amd.com/epd/processors/6.32bitproc/11.am486fami/12.am486dx/20037/20037.pdf AMD Am486 DE2 datasheet]
* [http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_1260_1270,00.html AMD: Enhanced Am486 Microprocessors]
* [http://www.digital-daily.com/editorial/amd-history/index02.htm AMD: 30 Years of Pursuing the Leader. Part 2]
* [http://www.cpu-collection.de/?tn=0&l0=co&l1=AMD&l2=486%20DX cpu-collection.de] AMD Am486 processor images and descriptions
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