Core 2 duo processors

Well its more in depth than that.

What the book was talking about was the Pentium D. A Pentium D had two Pentium 4 based CPUs on one processor tied together over the FSB to make one CPU.

A Core 2 Duo is actuall a naitive CPU. Its one CPU with two cores on the die but it is based off of the Pentium M which is based off of Intels Pentium III Coppermine design. In the end the Pentium III was based on the original Pentium.

So in the end it is kind of like having two Pentiums on one die but they are much faster and have much better IPC per cycle.

Pentium Dual Core is basically the same as a Core2, just a Core2 with less cache.

Pentium D is two Pentium 4 cores crammed in 1 cpu with 2 dies.