The K6-2 was a significant improvement over the K6. It built upon the K6's processing core, with the addition of 21 new instructions called "3D Now!". These are SIMD (Single Instruction Multiple Data) instructions designed to enhance the 3D geometry capability of the chip's floating point unit. This allowed the K6-2 to overcome the handicap of the slow (relative to Intel) CPU which the K6 owned.
The K6-2 also saw the introduction of a 100 MHz front side bus. This was only available to owners of new Super Socket 7 motherboards which also included features such as AGP. All of these features helped to give the K6-2 performance fast enough to be a credible challenger to the dominant
Pentium II. Performance of the two chips was broadly similar: the K6-2 tending to be faster for general-purpose
computing, the Intel part clearly superior at floating-point tasks. The K6-2 was a very successful chip and provided AMD with the marketing base and the
financial stability it would need to introduce the Athlon.
The K6-2 was originally manufactured in speeds of 266 & 300 MHz in May 1998. The 300 MHz chip saw the introduction of the 100 MHz bus over the conventional 66 MHz bus used by the 266 MHz chip. August 1998 a 333 MHz version on a 95 MHz bus has been released and was quickly followed by a 350 MHz version on the 100 MHz bus. November 1998 saw the release of the 366, 380 and 400 MHz versions of the chip. This has been followed by the release of a 450 MHz K6-2 in February 1999 and the 500 MHz version in August 1999.