i686 is an unofficial name given to the similar instruction sets used by several Intel and Intel-compatible microprocessors based on, or compatible with, the Intel P6 microarchitecture. It isn't an official Intel designation but a shorthand derived from the fact that the P6 microarchitecture is two generations on from Intel's i486 instruction set, which was the last to use that numerical nomenclature officially. The name is often used when configuring compilers. i686 Processors Intel Pentium… (More on I686)