] This series of articles takes a look at the consumer
] desktop processors that have borne the Pentium name,
] beginning with the original Pentium up through today's
] Pentium 4 (Prescott) and Pentium M divisions. The
] overview is general enough that for the most part it
] should be accessible to the nonspecialist, and it should
] give you a sense of the major differences between each
] generation of Pentiums.

Perhaps the best article I have ever read overviewing the Pentium architecture, and its advances. The article is an easy read, though if its been a while since you've read something like P&H (Patterson and Hennessy), you might have some trouble.

The Pentium: An Architectural History