• A multiprocessor system is an interconnection of two or more CPUs with memory and input-output equipment.
  • The term “processor” in multiprocessor can mean either a central processing unit (CPU) or an input-output processor (IOP).
  • Multiprocessors are classified as multiple instruction stream, multiple data stream (MIMD) systems
  • The similarity and distinction between multiprocessor and multicomputer are
    • Similarity
      • Both support concurrent operations
    • Distinction
      • The network consists of several autonomous computers that may or may not communicate with each other.
      • A multiprocessor system is controlled by one operating system that provides interaction between processors and all the components of the system cooperate in the solution of a problem.
    • Multiprocessing improves the reliability of the system.
    • The benefit derived from a multiprocessor organization is an improved system performance.
      • Multiple independent jobs can be made to operate in parallel.
      • A single job can be partitioned into multiple parallel tasks.
    • Multiprocessing can improve performance by decomposing a program into parallel executable tasks.
      • The user can explicitly declare that certain tasks of the program be executed in parallel.
        • This must be done prior to loading the program by specifying the parallel executable tasks.
      • The other is to provide a compiler with multiprocessor software that can automatically detect parallelism in a user’s program.
    • Multiprocessor are classified by the way their memory is organized.
      • A multiprocessor system with common shared memory is classified as a shared-memory or tightly coupled multiprocessor.
      • Tolerate a higher degree of interaction between tasks 
  • Each processor element with its own private local memory is classified as a distributed-memory or loosely coupled system.
    • Are most efficient when the interaction between tasks is minimal