This document discusses multiprocessor computer systems. It begins by defining a multiprocessor system as having two or more CPUs connected to a shared memory and I/O devices. Multiprocessors are classified as MIMD systems. They provide benefits like improved performance over single CPU systems for tasks like multi-user/multi-tasking applications. Multiprocessors are further classified as tightly-coupled or loosely-coupled based on shared vs distributed memory. Common interconnection structures discussed include bus, multport memory, crossbar switch, and hypercube networks.

1. Department: Information Technology
Computer Organization
Multiprocessor
Presented By:
Neelkumar J Patel
5/8/2017

2. Contents
• Introduction
• Why Choose a Multiprocessor?
• How multiprocessor are classified?
• Interconnection structures
• References
5/8/2017

3. Introduction
• Multiprocessor system is an interconnection of two or
more CPUs with memory and input-output equipment
• The components that forms multiprocessor are
CPUs IOPs connected to input –output devices ,
and memory unit that may be partitioned into a
number of separate modules.
• Multiprocessor are classified as multiple
instruction stream, multiple data stream (MIMD)
system.
5/8/2017

4. Why Choose a Multiprocessor?
• A single CPU can only go so fast, use more than
one CPU to improve performance
• Multiple users
• Multiple applications
• Multi-tasking within an application
• Responsiveness and/or throughput
• Share hardware between CPUs
5/8/2017

5. What you the difference between
Multiprocessor and Multicomputer?
Multiprocessor
• A multiprocessor system is simply a
computer that has more than one
CPU on its motherboard.
• Multiprocessing is the use of two or
more central processing units
(CPUs) within a single computer
system.
Multicomputer
• A computer made up of several
computers. The term generally refers
to an architecture in which each
processor has its own memory rather
than multiple processors with a
shared memory
5/8/2017

6. How multiprocessor are classified?
• Multiprocessor are classified by the way their
memory is organized, mainly it is classified
into two types
1. Tightly coupled multiprocessor
2. Loosely coupled multiprocessor
5/8/2017

7. Tightly coupled Multiprocessor
• A multiprocessor is a tightly coupled
computer system having two or more
processing units (Multiple Processors) each
sharing main memory and peripherals, in
order to simultaneously process programs
• Tightly coupled Multiprocessor is also know as
shared memory system
5/8/2017

8. Loosely-coupled multiprocessor
• Loosely-coupled multiprocessor systems
(often referred to as clusters ) are based on
multiple standalone single or dual processor
commodity computers interconnected via a
high speed communication system.
• Loosely-coupled multiprocessor is also known
as distributed memory.
• Example
A Linux beowulf cluster
5/8/2017

9. Difference b/w Tightly coupled and
Loosely coupled multiprocessor
Tightly coupled
• Tightly-coupled systems
physically smaller than
loosely-coupled system.
• More expensive .
Loosely coupled
• It is just opposite of tightly
coupled system.
• Less expensive.
5/8/2017

10. Interconnection Structures
• The physical forms for establishing an
interconnection network .
1. Time shared common bus.
2. Multiport memory.
3. Crossbar switch
4. Multistage switching network.
5. Hypercube system.
5/8/2017

11. 1. Time –shared common bus.
• A system common bus multiprocessor system
consists of a number of processors connected
through path to a memory unit.
5/8/2017
Memory Unit
CPU 1 IOP 1CPU 3CPU 2 IOP 2

12. 2. Multiport Memory
• A multiport memory system employs separate
buses between each memory module and
each CPU.
5/8/2017

13. 3. Cross bar switch
5/8/2017

14. 4. Multistage switching Network
• The basic component of a multistage network
is a two- input , two- output interchange
switch.
5/8/2017

15. 5. Hypercube Interconnection
• The hypercube or binary n-cube multiprocessor
structure is loosely coupled system composed of
N=2n processor interconnected in an n-dimensional
binary cube.
• Hyper cube structures for n = 1,2,3.
011 111
0 01 11
010 110
001 101
1 00 10 000 100
One –cube Two – cube Three cube
5/8/2017

16. References
• M.Morris Mano Computer System
Architecture , Third Edition , Pearson
Education.
• Aakriti Sharma, Advance Computer
Architecture in simple steps.
5/8/2017

17. Thank you….
5/8/2017