(Known as "P6" during development) Intel's successor to the Pentium processor, in development Jan 1995, generally available 1995-11-01. The P6 has an internal RISC architecture with a CISC-RISC translator, 3-way superscalar execution, and out-of order execution (or "speculative execution", which Intel calls "Dynamic Execution"). It also features branch prediction and register renaming, and is superpipelined (14 stages).
The P6 is made as a two-chip assembly: the first chip is the CPU and 16 kilobyte first-level cache (5.5 million transistors) and the other is a 256 (or 512) kilobyte second-level cache (15 million transistors). The first version has a clock rate of 133 Mhz and consumes about 20W of power. It is about twice as fast as the 100 MHz Pentium. The original 0.35 micron versions of the Pentium Pro released on 1995-11-01 run at 150 and 166 Mhz for desktop machines and up to 200 Mhz for servers. Heat disspation is about 20 Watts.
The Pentium Pro is optimised for 32-bit software and runs 16-bit software slower than the original Pentium. The successor was the Pentium II.