How can AMD K8 and AMD64 describe the same processor? Are AMD K8 and AMD64 the same thing?
AMD K8 is a processor microarchitecture, which was the first to implement the AMD64 instruction set as an extension to the x86 architecture.
The following x86 processors use the AMD K8 microarchitecture:
Think of it as being analogous to the Intel versions; the Nehalem and Sandy Bridge microarchitectures have the Intel 64 instruction set extension and are implemented in the processors like Core 2 Duo and Core i7.