This preview shows page 1. Sign up to view the full content.
Unformatted text preview: ization of a typical multiprocessing system is shown in Figure 14.9.
Tightly and Loosely Coupled Multiprocessing Systems
Multiprocessing systems are basically of two types - tightly-coupled systems and
loosely-coupled systems. In tightly-coupled systems, there is a single system-wide
primary memory that is shared by all the processors. On the other hand, in looselycoupled systems, the processors do not share memory, and each processor has its
own local memory. In contrast to the tightly-coupled systems, the processors of
loosely-coupled systems can be located far from each other to cover a wider
Difference between Multiprogramming and Multiprocessing
Multiprogramming is the interleaved execution of two or more processes by a
single-CPU computer system. On the other hand, multiprocessing is the
simultaneous execution of two or more processes by a computer system having
more than one CPU. To be more specific, multiprogramming involves executing a
portion of one program, then a segment of another, etc., in brief consecutive time
periods. Multiprocessing, however, makes it possible for the system to
simultaneously work on several program segments of one or more programs.
Advantages and Limitations of Multiprocessing
Multiprocessing systems typically have the following advantages: 1.
Due to multiplicity of processors, multiprocessor
systems have better performance than single-processor systems. That is, the
multiple processors of such a system can be utilized properly for providing shorter
response times and higher throughput than a single-processor system. For
example, if there are two different programs to be run, two processors are
evidently more powerful than one because the programs can be simultaneously run
on different processors. Furthermore, if a particular computation can be partitioned
into a number of subcomputations that can run concurrently, in a multiprocessor
system all the subcomputations can be simultaneously run with each one on a
different processor. However, the speed-up ratio with n processors is not n, but...
View Full Document
This document was uploaded on 04/07/2014.
- Spring '14