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1. introduction

In the previous sections of this course. we have concentrated on singleprocessor architectures and techniques to improve upon their performance, such as:

– Efficient algebraic hardware implementations

– Enhanced processor operation through pipelined instruction execution and multiplicity of functional units

– Memory hierarchy

– Control unit design

– I/O operations

Through these techniques and implementation improvements, the processing power of a computer system has increased by an order of magnitude every 5 years. We are (still) approaching performance bounds due to physical limitations of the hardware.

  • Several approaches of parallel computer are possible

– Improve the basic performance of a single processor machine

Architecture / organization improvements

Implementation improvements

SSI -->VLSI -->ULSI

Clock speed

Packaging

– Multiple processor system architectures

Tightly coupled system

Loosely coupled system

Distributed computing system

- Parallel computer: SIMD computer, MIMD computer

2. multiple processor systems

System with multiprocessor CPUs can be divided into multiprocessor and multicomputers. In this section we will first study multiprocessors and then multicomputers

Shared-memory multiprocessor

A parallel computer in which all the CPUs share a common memory is called a tightly coupled systems

Figure 16.1. Tightly coupled systems, Shased-memory multiprocessor

  • The features of the system are as follow.

– Multiple processors

– Shared, common memory system

– Processors under the integrated control of a common operating system

– Data is exchanged between processors by accessing common shared variable locations in memory

– Common shared memory ultimates presents an overall system bottleneck that effectively limits the sizes of these systems to a fairly small number of processors (dozens)

Message-passing multiprocessor

A parallel computer in which all the CPUs has a local independent memory is called a loosely coupled systems

Figure 16.2. Loosely coupled systems, Message-passing multiprocessor

  • The features of the system are as follow.

– Multiple processors

– Each processor has its own independent memory system

– Processors under the integrated control of a common operating system

– Data exchanged between processors via interprocessor messages

– This definition does not agree with the one given in the text

Distributed computing systems

Now we can see the message-passing computer that multicomputer are held togerther by network.

– Collections of relatively autonomous computers, each capable of independent operation

– Example systems are local area networks of computer workstations

+ Each machine is running its own “copy” of the operating system

+ Some tasks are done on different machines (e.g., mail handler is on one machine)

+ Supports multiple independent users

+ Load balancing between machines can cause a user’s job on one machine to be shifted to another

Performance bounds of multiple processor systems

  • For a system with n processors, we would like a net processing speedup (meaning lower overall execution time) of nearly n times when compared to the performance of a similar uniprocessor system
  • A number of poor performance “upper bounds” have been proposed over the years

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
When we have data register and address registers in user mode (visible registers) then why we need MAR and MBR
Hassan Reply
with the given example MOV BX,AX describe the sequence that will be followed using instruction state diagram
Gireesh Reply

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Source:  OpenStax, Computer architecture. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10761/1.1
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