After AMD's plans with the K5 turned into a debacle, AMD again claimed that they had the solution to make them more than just discount alternatives to Intel:
A chip with the power of a Pentium Pro, with MMX support and intended to fit into a standard socket 7.
AMD delivered its much anticipated K6 chip in April of 1997, beating Intel's Pentium II to the market by a month.
AMD showed their commitment to establishing themselves in the market when they purchased NexGen in 1996 and with it, the design for the
Nx686 processor. NexGen had been intending to market this chip in its own socket, but AMD changed the design to fit the
standard socket 7, added MMX support, and renamed it the K6. Despite the name implying a design evolving from the K5, it is in fact a totally different design
that was created by the NexGen team and adapted after the AMD purchase.
The K6 was originally launched running at speeds of 166 and 200 MHz in April 1997. It was followed by a 233 MHz version later in the summer of 1997. The release of
the 266 MHz version of this chip was not until spring 1998 when AMD were able to move to the 0.25 micron manufacturing process. The final iteration of the K6
design was released in May 1998 running at 300 MHz and continued with the K6-2.
Initially, the AMD K6 processors used Pentium II Rating (PR2) to designate their speed. The PR2 rating was dropped because the rated frequency of the processor was the same as the real frequency. This item was made in the month the K6 was released (week 17/1997 = April 21st - 27th, 1997) and has the initial PR2 marking.