Pentium D is a dual-core version of Pentium 4, and Pentium Extreme Edition is a Pentium D with HyperThreading technology enabled. Pentium D and Pentium Extreme Edition CPUs can be found using two different core versions: Smithfield and Presler. In this tutorial we will talk about these two core versions and we will also list all Pentium D and Pentium Extreme Edition models released to date.