Multi processing system

 Multi processing system

·         Multi processesor system is the sytem that contain two or more processors or CPUS and has ability to simultaneously execute   several programs. Hence the name multi-processor

In such a system, multiple processor share the clock, bus, memory and peripheral devices.

·         A multi processor system is also known as parallel system

·         Multi processor system are categorized into two different types:

             single user operating system  

2.      Multi user operating system 

3.       Batch processing operating system

4.      Multi programming operating system 

5.     Multi tasking operating system 

6.       Multiprocessing operating system

7.       Time sharing operating system

8.     Real time system  

1.       Symmetric multiprocessing(SMP)

2.       Asymmetric multiprocessing(ASMP)

·         Symmetric multi processing (SMP)

 

1.       In SMP each processor runs an identical copy of the operating system.

2.       The processor can communicate with each other and execute these copies concurrently.

3.       Therefore SMP exhibit peer-to-peer relationship.

·         Asymmetric multiprocessing (ASMP)

 

1. In ASMP, different processor do different things i.e. they are not identical thus, there is imbalance among the processors. hence the name asymmetric.

2. in ASMP each processors is given a specific task and do not share equal load .

3. There is master slave relationship between the processors.

     

Advantage and disadvantages 

of multiprocessing system

 

Advantages of multiprocessing system

• 1.       Improved reliability .multiprocessing system have better reliability than single-processor because of the presence of multiple processors. If one of the processors break down ,the other processors automatically takes over the system work hold until repaired are made. Hence a complete breakdown of such system can be avoided.
• 2.       Improved throughout. Throughout is the number of jobs executed per unit time. With the use of multiple processors, parallel processing of segment of programs is  possible .
• 3.       Lowered turnaround time. Turnaround time is the difference between the time user submits his jobs to system for processing and the time he receive results.
• 4.       Efficient utilisation of all resources. In addition to the processors , it also facilities more efficient utilisation of all the other devices of the computer system.
• 5.       Economical. The clock, bus, peripheral devices and memory are shared . as a result, it is cheaper to have multiprocessors systems than multiple single processors system.

 

 

 Disadvantages of multiprocessing system

• 1.       A very sophisticated operating system is required to schedule, balance and coordinate the input, output and processing activities of multiple CPU's.
• 2.       A large main memory is required for accommodating the sophisticated operating system along with several users programs.
• 3.       Such  system are very expensive in addition to the high charges paid initially, the regular operation and maintenance of these systemis also costly affair

 

Comparison between multi 

programming and multi 

processing