
17-2
x86 MICROPROCESSORS
processors with names Pentium II and Pentium III were released. Both of them were
based on the P6 microarchitecture, with minor enhancements/differences for each of
them, the details of which are as listed in Table 17.1. Intel’s P6 microarchitecture, first
instantiated in the Pentium Pro was, by any calculation, a super success story. Its perfor-
mance was significantly better than that of the Pentium.
Table 17.1 Comparison of Three P6 Processors
Pentium Pro Pentium-II Pentium- III
Year of release November 1,1995 May 7, 1997 February 26, 1999
Clock speed at
introduction
200 MHz 300 MHz 500 MHz
Transistor count 5.5 million ...