Advantages And Disadvantages Of Minicomputer System

Resource utilization - It refers to the process of utilizing the resources by sharing them between the software and hardware of the system and optimizing the resource utilization between multiple users.

A. Mainframe or minicomputer system - multiple users accessing the system from different terminals of a mainframe or minicomputer system, these users share resources and information, operating system makes sure that the resources are utilized equally between all users, when resource utilization is maximum the operating system is developed in a way to maximize the resource utilization by making sure that all the CPU time, memory and I/O are used efficiently.

B. Workstations connected to Servers - Users sit at workstations connected to networks

Advantages of Multiprocessor systems:

1. Increased Throughput – Increasing the number of processors more work can be completed in a short span of time.

2. Economy of Scale – It is cost saving as multiprocessor systems cost less than single processor system as they share memory, buses, peripherals etc. Multiprocessor system thus saves money as compared to multiple single systems. If many programs operate on the same data, it is cheaper to store that data on one single disk and shared by all processors instead of using many copies of the same data.

3. Increased Reliability – In multiprocessors the workload is shared among several processors, if one processor fails, then its failure may slightly slow down the speed of the system, but system will work smoothly.

Disadvantage of Multiprocessor system it is more complex in both hardware and software. The system contains multiple CPU’s if one of the CPU efficiency goes down, both are halted. The solution to t is he process that is being executed is expensive as when the halted process is moved to another pair of CPU’s and the failed instruction is then

Single Processor Systems – In single processor system only one process executes at a time, which causes no difficulties, since access to integer A will always be the copy at the highest level of the hierarchy. In Multitasking is where the CPU is switched back and forth among various processes, utmost care must be taken to make sure that, if multiple processes wants to access A, then each of these processes will acquire the most recently updated value of A.

B. Multiprocessor Systems – In multiprocessor system the situation will be more complicated, each CPUs contains a local cache along with the local registers. In such case, a copy of A may exist simultaneously in several caches as the CPUs execute parallelly and by making sure that update to the value of A in one cache is immediately reflected in all other caches where A resides. This situation is called cache coherency, and it is a hardware issue (handled below the operating-system level).

C. Distributed Systems – In distributed systems the situation will be much more complex as s copies (or replicas) of the same file can be kept on different computers. Even though various replicas may be accessed and updated simultaneously, few distributed systems make sure that when a copy is updated in one place, all other copies are brought up to date at