Am386
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Am386DX-40.jpg
The Am386 central processing unit microprocessor was released by AMD in 1991. A 100%-compatible clone of the Intel 80386 design, it sold millions of units and positioned AMD as a legitimate competitor to Intel, rather than just a second source for Intel's x86 CPUs.
While the CPU was essentially ready to be released prior to 1991, Intel kept it tied up in court. AMD had previously been a second-source manufacturer of Intel's designs, and AMD's interpretation of the contract was that it covered all of them. Intel, however, claimed that the contract only covered the 80286 and prior processors. After a few years in the courtrooms, AMD finally won the case and the right to sell their Am386. This paved the way for competition in the CPU market and thus lowered the cost of owning a PC.
While Intel's 386 design peaked at 33 MHz, AMD released a 40 MHz version of both its 386DX and 386SX, extending the lifespan of the architecture. The AMD 386DX-40 was very popular with small manufacturers of PC clones and with budget-minded computer enthusiasts, because the 386DX-40 could match or even slightly outperform a 486SX-25 in popular benchmarks while costing less, and even edged ahead of the 486DX-33 in many real-world performance tests. This was mostly because the Am386DX-40 ran its front side bus at the same 40 MHz speed as the processor itself, while the fastest 486 of the time only ran a 33MHz FSB. Performance could be further boosted with the addition of an inexpensive 387DX math coprocessor, although the floating-point performance was nowhere near that of the 486DX, making the Am386DX in any variation a poor choice for 3D games or CAD. However, both were niche markets in the early 1990s and the chip sold well, first as a mid-range, and then as a budget chip. Although the chip often struggled under Windows 95's increased CPU and memory requirements, it was sold into the mid 1990s, both as an embedded chip, and on budget motherboards for those who were only interested in running MS-DOS or Windows 3.1 applications.
External links
- AMD.com: Am386® Family 32-bit Processors (http://www.amd.com/epd/processors/6.32bitproc/10.am386fami/)
- cpu-collection.de: Pictures (http://www.cpu-collection.de/?l0=co&l1=AMD&l2=386%20DX)
- AMD: 30 Years of Pursuing the Leader. Part 2 (http://www.digital-daily.com/editorial/amd-history/index02.htm)