The P6 microarchitecture is the sixth-generation Intel x86 microarchitecture, implemented by the Pentium Pro microprocessor that was introduced in November 1995. It is frequently referred to as i686. It was planned to be succeeded by the NetBurst microarchitecture used by the Pentium 4 in 2000, but was revived for the Pentium M line of microprocessors. The successor to the Pentium M variant of the P6 microarchitecture is the Core microarchitecture which in turn is also derived from P6.
Die shot of Deschutes core
x86 is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the 8086 microprocessor and its 8088 variant. The 8086 was introduced in 1978 as a fully 16-bit extension of 8-bit Intel's 8080 microprocessor, with memory segmentation as a solution for addressing more memory than can be covered by a plain 16-bit address. The term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 and 80486. Colloquially, their names were "186", "286", "386" and "486".
The x86 architectures were based on the Intel 8086 microprocessor chip, initially released in 1978.
Intel Core 2 Duo, an example of an x86-compatible, 64-bit multicore processor
AMD Athlon (early version), a technically different but fully compatible x86 implementation
Am386, released by AMD in 1991