Intel 64 is Intel's implementation of x86-64. It is used in newer versions of Pentium 4, Celeron D, Xeon and Pentium Dual-Core processors, the Atom D510, N450, N550, N2600 and N2800 and in all versions of the Pentium Extreme Edition, Core 2, Core i7, Core i5, and Core i3 processors.
Read more about this topic: Amd64