The AMD opteron processor for multiprocessor servers
C.N. Keltcher, Kevin McGrath, Ashfaq Ahmed, Pat Conway · IEEE Micro · 2003
Representing AMD's entry into 64-bit computing, Opteron combines the backwards compatibility of the X86-64 architecture with a DDR memory controller and hypertransport links to deliver server-class performance. These features also make Opteron a flexible, modular, and easily connectable component for various multiprocessor configurations.