An earlier Pentium II-class CPU chip from AMD. The first models were introduced in 1997 at 166 MHz, 200 MHz and 233 MHz clock speeds. Originally engineered by NexGen, AMD acquired the company in 1996. The K6 contained the MMX instructions used in Pentium MMX and Pentium II CPUs and plugged into Socket 7 on Pentium motherboards.

The second-generation K6-2, introduced in 1998, improved performance and added AMD's 3DNow 3D instructions for faster rendering of games and animation. The K6-3 was introduced in 1999 with improved performance and greater onboard cache. The K6 series was superseded by the Athlon. See Athlon and K7.