Multiprocessor System

Multiprocessor system which provide processing using more than one central processing units (CPU) or cores single computer. Multiple processers commonly share memory, peripheral devices which provide simultaneously processing of programs. The basic purpose of using multiprocessing system to speed up the execution of system or to boost up the speed of computing, cost effectiveness, performance and also provide increased availability and reliability. Parallel proceeding of computation can be done by two ways:

1-Multiple independent jobs operate in parallel.

2-A single job can be broken down in multiple parallel tasks.

The MIMD system is a multiprocessor.

Keywords: LCM loosely coupled microprocessor, SM shared memory, TCM tightly coupled microprocessor, MIMD multiple instruction multiple data, IOP I/O operation per second, DM distributed memory.

Components of Multiprocessor

Components required for MP are

• CPUs
• IOPs
• I/O devices
• Memory

Note: IOPs usually not included in components of multiprocessor but it is used to measure the performance speed of CPUs.

Classification:

According to memory organization the microprocessor is classified as:

1-Shared memory/ tightly coupled microprocessor.

2-Distributed memory/ loosely coupled microprocessor.

• Tightly coupled microprocessor

If the multiple processors are commonly shearing the memory & peripheral devices to proceed the programs simultaneously then it will call as tightly coupled microprocessor also it can be called as SM. It is more expensive than LCM. Client server processing is an example of TCM.

• Loosely coupled microprocessor

These are the systems that are also called distributed memory microprocessors depends on multiple stand-alone single or dual processor commodity computers is the use of huge numbers of already-available computing components for parallel computing which are interconnected via a high speed communication system Gigabyte Ethernet commonly use. It is also known as DM. it is less expensive. In LCM each processor has its own dedicated resources as shown below. A Linux Beowulf cluster is an example of LCM.

• Symmetric multiprocessor

symmetric multiprocessor in which different individual tasks are assign to different processor. Like one processor is assign with a complete job and other will other job.

• Asymmetric multiprocessor

Asymmetric multiprocessor in which a job is divided into sub parts and each part is assigned to individual processor. It is called master-slave method in which one processor work as a master which assign the jobs to other processors they are called as salve processors and they follow the instructions of master processor to perform the task.

Advantages

• Multiple user
• Multiplication Applications
• Multi-tasking within an application
• Responsiveness
• Share hardware b/w CPUs

Clustered System

Clustered system provide the facility to make a single logical unit or a group of multiple computers connected through LAN. Computers worked together each connected computer in a set perform a same task which is controlled and scheduled by software. It provides high processing speed, better data integrity, large capacity of storage, wider availability of resources and superior reliability. It is used by many organizations to maximize the performance time, enhance database storage and implement high speed storing and retrieving technique. It is mostly used by organizations when high speed processing is required. In this system computers work like client server. Cluster system is shown as ­­­­­­­­­­­­­­­­­­

 Clustered system are

1. Asymmetric clusters
2. Symmetric clusters

• Asymmetric clusters

Which consist two or more servers one is on standby mode and other is monitoring the other work.

• Symmetric cluster

All computers in cluster work together (or run applications simultaneously) and monitor each other 

• Tightly coupled cluster

A group of machines that are largely depend on each other. It is used where latency is important factor in application. Web cluster is an example of tightly coupled cluster.

• Loosely coupled cluster

It is basically a group of machines or a group of groups which can self-sufficiently operate. Communication between nodes or between sub clusters sometimes done via a queuing system.

Difference Between multiprocessor and clustered system

• Multi processers tied together.
• Cluster system different computers tied together through LAN.
• Multiprocessor system do not use networking.
• Cluster system use networking like LAN.
• Multiprocessor provide time saving facility.
• Cluster system provide availability.
• The processers share common system clock also common data structure.
• Multiprocessor consists of cores which perform different tasks.
• Clusters system different CPUs work together for specific task.

 

Linux Operating System