NexGen, Inc. was a private semiconductor company based in Milpitas, California, that designed x86 microprocessors until it was purchased by AMD on January 16, 1996. NexGen was a fabless design house that designed its chips but relied on other companies for production. NexGen's chips were produced by IBM's Microelectronics division in Burlington, Vermont, alongside PowerPC and DRAM parts.
The company was best known for the unique implementation of the x86 architecture in its processors. NexGen's CPUs were designed very differently from other processors based on the x86 instruction set at the time: the processor would translate code designed to run on the traditionally CISC-based x86 architecture to run on the chip's internal RISC architecture. The architecture was used in later AMD chips such as the K6, and to an extent most x86 processors today implement a "hybrid" architecture similar to those used in NexGen's processors.
The company went public in 1994, and was bought by AMD in 1995 for $850 million. The technology forms the platform architecture for all of AMD's current microprocessors. It was an unusual start-up in its time as the original funding came from corporate investors, Compaq and Olivetti, Using IBM's multichip module (MCM) technology, NexGen combined the 586 and 587 die in a single package. The new device, which used the same pinout as its predecessor, was marketed as the Nx586-PF100 to distinguish it from the FPU-less Nx586-P100.
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Compaq, which had backed the company financially, announced its intention to use the Nx586 and even struck the name "Pentium" from its product literature, demos, and boxes, substituting the "586" moniker, but never used NexGen's chip widely. Instead, Alaris, Inc., a smaller computer systems maker, became the first company to ship a computer with the Nx586 in fall 1994.
AMD purchased NexGen when AMD's K5 chip failed to meet performance and sales expectations. Some NexGen customers were even given free AMD K5 CPUs with motherboards in exchange for sending in their NexGen hardware.
Development of AMD's internal K5 successor was halted in favor of continuing from NexGen's Nx686 designs, eventually becoming K6.