Pentium - Pentium-branded Processors - P6 Microarchitecture Based

P6 Microarchitecture Based

In parallel with the P5 microarchitecture, Intel developed the P6 microarchitecture and started marketing it as the Pentium Pro for the high-end market in 1995. It introduced out-of-order execution and an integrated second level cache on dual-chip processor package. The second P6 generation replaced the original P5 with the Pentium II and rebranded the high-end version as Pentium II Xeon. It was followed by a third version called the Pentium III and Pentium III Xeon, respectively. The Pentium II line added the MMX instructions that were also present in the Pentium MMX.

Versions of these processors for the Laptop market were initially called Mobile Pentium II and Mobile Pentium III, later versions were called Pentium III-M. Starting with the Pentium II, the Celeron brand was used for low-end versions of most Pentium processors with a reduced feature set such as a smaller cache or missing power management features.