Amdahl law to measure speed up performance, Computer Engineering

Assignment Help:

Q. Amdahl Law to measure speed up performance?

Remember that speed up factor assists us in knowing relative gain attained in shifting execution of a task from sequential computer to parallel computer and performance doesn't increase linearly with rise in number of processors. Because of above reason of saturation in 1967 Amdahl's law was derived. Amdahl's law defines that a program includes 2 types of operations that is complete sequential operations that should be done serially and complete parallel operations that can be executed on numerous processors. The declaration of Amdahl's law can be illustrated with help of following example. 

Let's discuss a problem say P that has to be solved with the help of parallel computer. In accordance with Amdahl's law there are principally two types of operations. So the problem would have a number of serial operations and a number of parallel operations. We already know that this requires T (1) amount of time to carry out a problem using a sequential machine and sequential algorithm. The time to calculate sequential operation is a fraction α (alpha) (α ≤ 1) of total execution time that is T (1) and time to calculate parallel operations is (1- α). So S (N) can be calculated as below:

100_Amdahl Law to measure speed up performance.png

Dividing by T(1)

1768_Amdahl Law to measure speed up performance1.png

Consider the value of α is amid 0 and 1. Now let's put a number of values of α and calculate speed up factor for rising values of number of processors.  We find that S(N) continue reduces with increase in value of α (which is number of serial operations as displayed in Figure below). 

1461_Amdahl Law to measure speed up performance2.png

Figure: Speed-up vs. Number of Processors

The graph in Figure clearly demonstrates that there is a bottleneck caused because of serial operations in parallel computer. Even when numbers of serial operations are more after rising number of processors speed up factor S (N) degrades. 

The sequential fraction which is α can be compared with speed up factor S (N) for a permanent value of N let's say 500. Figure below demonstrates a pictorial view of effect of Amdahl's law on speed up factor.

1241_Amdahl Law to measure speed up performance3.png

Figure: (n) vs. α (Graph is not to scale)


Related Discussions:- Amdahl law to measure speed up performance

Propositional logic - artificial intelligence, Propositional Logic - artifi...

Propositional Logic - artificial intelligence: This is a limited logic, which permit  us to write sentences about propositions - statements about the world - which can either b

Why must a modem be used to transmit binary data, Why must a modem be used ...

Why must a modem be used to transmit binary data through a PSTN? (1) Use sketches and additional text to describe the following modulation methods. (a) Amplitude shift keying (b) F

The statement vline is used to insert vertical lines, Like ULINE the statem...

Like ULINE the statement VLINE is used to insert vertical lines. No , Vline is not used to insert vertical lines.

Determine the odd parity bit for f, Q. Determine the odd parity bit for F. ...

Q. Determine the odd parity bit for F. Q. Convert the following from binary to decimal, hexadecimal, BCD and octal. a) 1000000011   b) 0001010110101  c) 1 Q. Convert the f

Receive a message, Receive a message. tid is integer task identifier of tra...

Receive a message. tid is integer task identifier of transmitting process supplied by user and msgtag is message tag supplied by user( must be non negative integer). The process re

Describe the forms tag, Now let's get a grip on how to add interactivity to...

Now let's get a grip on how to add interactivity to your web documents by way of the tag. With this tag you can add to your web pages a guestbook, surveys, order forms, ge

Reflexes - artificial intelligence, Reflexes - artificial intelligence: ...

Reflexes - artificial intelligence: If an agent decides upon and executes an action in response to a sensor input without consultation of its world, then this can be considere

Propositional logic, Propositional Logic: This is a fairly restrictive...

Propositional Logic: This is a fairly restrictive logic, that allows us to be write sentences about ¬propositions - statements about the world - that can either be true or

Software interface, what is software interface #Minimum 100 words accepted...

what is software interface #Minimum 100 words accepted#

Dbms, What is meant by concurrent execution of database transactions in a m...

What is meant by concurrent execution of database transactions in a multi user system

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd