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

Describe generic framework for electronic commerce, Describe generic framew...

Describe generic framework for electronic commerce Generic Framework for electronic commerce contains the Applications of EC   (like as banking, shopping in online stores and m

What is common control switching system, What is common control switching s...

What is common control switching system? Explain. Common Control Switching System: It is a functional block diagram of a common control switching system is demonstrated in figu

What do you mean by execution unit, Q. What do you mean by Execution Unit? ...

Q. What do you mean by Execution Unit? Execution unit performs all ALU operations. Execution unit of 8086 is of 16 bits. It also contains the control unit that instructs bus in

Discuss about fourth generation electronic computers, Fourth Generation (19...

Fourth Generation (1972-1984) The next generation of computer systems used the large scale integration (LSI -1000 devices per chip) and very large scale integration (VLSI - 100

Why 256 x 8 memory chips is require to design 2k x 8 memory, A number of 25...

A number of 256 x 8 bit memory chips are available. To design a memory organization  of 2 K x 8 memory. Identify the requirements of 256 x 8 memory chips and explain the details.

What is DRAM and what do you understand by DRAM refreshing, What is DRAM? ...

What is DRAM? What do you understand by DRAM refreshing? With the help of a block diagram, demonstrate how DRAM can be interfaced to a microprocessor. Dynamic RAM (DRAM) is bas

What are attributes, What are Attributes?  Attributes are declarative ...

What are Attributes?  Attributes are declarative tags in code that insert additional metadata into an assembly. There exist two types of attributes in the .NET Framework: Pred

Explain about parallel programming environment, Q. Explain about parallel p...

Q. Explain about parallel programming environment? The parallel programming environment comprises of a debugger, an editor, performance evaluator, programme visualizer for incr

Basic need of search engines, Q. Basic need of Search Engines? Search E...

Q. Basic need of Search Engines? Search Engines are programs which search the web. Web is a big graph with pages being the nodes and hyperlinks being the arcs. Search engines c

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