Pentium Pro

The Pentium Pro is the first sixth-generation x86-based microprocessor developed and manufactured by Intel and introduced on November 1, 1995. It was the first x86-based Intel processor to implement the P6 microarchitecture (sometimes termed i686), itself being the successor to the P5 architecture of the original Pentium.

While the Pentium and Pentium MMX had 3.1 and 4.5 million transistors, respectively, the Pentium Pro contained 5.5 million transistors. It was capable of both dual- and quad-processor configurations and only came in one form factor, the relatively large rectangular Socket 8.

The Pentium Pro was originally intended to replace the original Pentium (P5) in a full range of applications. Later, it was reduced to a more narrow role as a server and high-end desktop processor. Its role was later expanded to include supercomputers powered by the processors; the most notable being ASCI Red in 1996, which was the first computer to reach over one teraFLOPS and held the number one spot in the TOP500 list from 1997 to 2000. ASCI Red used a dual-processor configuration with two Pentium Pro CPUs on each computing node.

The successor to the Pentium Pro is the Pentium II Xeon in 1998 which in turn is also derived from P6.