Multiprocessors Interconnection Networks

• A multiprocessor system consists of multiple processing units connected via some interconnection network plus the software needed to make the processing units work together.
• A number of communication styles exist for multiprocessing networks. These can be broadly classified according to the communication model as shared memory (single address space) versus message passing (multiple address spaces).
  • Communication in shared memory systems is performed by writing to and reading from the global memory
  • Communication in message passing systems is accomplished via send and receive commands.
  • In both cases, the interconnection network plays a major role in determining the communication speed. Two schemes are introduced, namely static and dynamic interconnection networks.
    • Static networks form all connections when the system is designed rather than when the connection is needed. In a static network, messages must be routed along established links. (hypercube, mesh, and k-ary n-cube topologies)
    • Dynamic interconnection networks establish connections between two or more nodes on the fly as messages are routed along the links. (bus, crossbar, and multistage interconnection )