Multiprocessor Operating Systems


When two or more central processing units operate within a single computer system, it is referred as a multiprocessor system. In such computers, these multiple CPU’s have a close connection and communication to share data and programs. These multiple processors also share operating system resources such as memory, buses, printers, and other peripheral devices.

Multiprocessor systems are used when users need extremely high processing speed to process a high volume of data. In most of the cases, such operating systems are used to carry out scientific calculations or operations such as satellite processing, deep data analysis, and weather forecasting.

The entire task of a multiprocessing system is managed by an effective running operating system. This system allocates different tasks to multiple processors present in the system architecture. The multiprocessing systems are also designed to operate tasks which are multithreaded. These are tasks which are subdivided into smaller tasks to reduce the overall processing time.

The operating system assigns these small threads to different processors so that they can run independently resulting in improved performance. Some of the basic features of multi-processing systems are:

  • They support processes to run in parallel.
  • Multi-threading features improve performance reducing the overall operating time.
  • It is used in areas such as artificial intelligence, expert systems, image processing, etc.


Some of the advantages of multiprocessing systems are:

  • Increased throughput (increased number of processed programs per second)
  • Cost effective as it shares the same resources a single processor is using in a system.
  • Increased reliability – Distributed workload results in increased reliability of the overall computer system.


Some of the disadvantages of multiprocessing systems are:

  • Failure of even one of the processor negatively affects the overall speed of the operating system.
  • These systems are expensive
  • More sophisticated operating systems are required to manage programs and data.
  • The computer system requires a large main memory

Multiprocessing operating systems may be sub-categorized based on the number of processors, main memory, and the purpose of the operating system. Every processor is also symmetric and is dedicated to carrying a dedicated task.

These processors can also be assigned some specific tasks based on their processing power. Also, some hardware and software considerations may be required to develop these tasks. Some of the most common multiprocessor operating systems are UNIX and OS/2.

  • It dynamically shares resources among multiple processors in the system architecture.
  • It has Shared data and resources such as memory, buses, and peripheral devices.