Jannat

Parallel Organization

Presented by:Umma Khatuna Jannat

Traditionally, software has been written for serial computation:

To be run on a single computer having a single Central

Processing Unit (CPU); A problem is broken into a discrete series

of instructions.

Instructions are executed one after another.

Only one instruction may execute at any moment in time.

What is concurrent computing?

Parallel computing

In the simplest sense, parallel computing is the simultaneous use of multiple resources to solve a computational problem:

To be run using multiple CPUsA problem is broken into discrete parts that can be solved concurrentlyEach part is further broken down to a series of instructions Instructions from each part execute simultaneously on different CPUs

Parallel Processing

Parallel processing is also achieved by using multiple processors clustered together to process one part of a large function simultaneously to obtain results faster.

CPU

CPU

CPU

CPU

InstructionsProblem

Multiple Processor Organization

Single instruction, single data stream – SISD

Single instruction, multiple data stream – SIMD

Multiple instruction, single data stream – MISD

Multiple instruction, multiple data stream- MIMD

Characteristics of Parallel Processors…

Single Instruction, Single Data Stream ~SISD

A serial (non-parallel ) computerSingle instruction : only one instruction stream is being acted on by CPU during any one clock cycleSingle data :only one data stream is being used as input during any one clock cycleDeterministic executionThis is the oldest and even today, the most common type of computerExamples: older generation mainframes, minicomputers and workstations ,most modern day PCs.

SISD

Memory ControlProcessor

Data stream Instruction stream

Single Instruction, Multiple Data Stream - SIMD

Single machine instruction Controls simultaneous executionNumber of processing elementsLockstep basisEach processing element has associated data memoryEach instruction executed on different set of data by different processorsVector and array processors

Memory

Memory

Memory

Processor

Processor

Processor

ControlInstruction stream

Instruction stream

Instruction stream

Data stream

Data stream

Data stream

SIMD

A single data stream is fed into multiple processing units.

Each processing unit operates on the data independently

via independent instruction streams.

multiple algorithms attempting to crack a single coded

message.

MULTIPLE INSTRUCTION, SINGLE DATA STREAM - MISD

Memory

Data stream

ProcessorInstruction stream

Control

Data stream

Data stream

Instruction stream

Instruction stream

Processor

Processor Control

Control

Currently, the most common type of parallel computer. Most modern computers fall into this category. Multiple Instruction: every processor may be executing a different instruction stream Multiple Data: every processor may be working with a different data stream Examples: most current supercomputers, networked parallel computer clusters and "grids", multi-processor

MULTIPLE INSTRUCTION, MULTIPLE DATA STREAM- MIMD

Uses for Parallel Computing

Historically, parallel computing has been considered to be “the high end of computing", and has been used to model difficult scientific and engineering problems found in the real world, Some examples:Atmosphere ,Earth , EnvironmentPhysics-applied ,nuclear, high pressure ,fusion, photonicsBioscience , Biotechnology , GeneticsChemistry, Molecular SciencesGeologyMechanical Engineering-from prosthetics to spacecraftElectrical Engineering, Circuit DesignComputer Science, Mathematics

Uses in Today’s world…

Today, commercial applications provide an equal or greater driving force in the development of faster computers. These applications require the processing of large amounts of data in sophisticated ways for examples:

DatabasesWeb search engines, web based business servicesMedical imaging and diagnosisPharmaceutical designManagement of national and multi-national corporations

Thank You