Explain potential of parallelism, Computer Engineering

Potential of Parallelism

Problems in the actual world differ in respect of the amount of inherent parallelism intrinsic in respective problem domain. Some problems can be easily parallelized. Conversely, there are some inherent chronological problems (e.g. computation of Fibonacci sequence) whose parallelization is almost impossible. The extent of parallelism can be enhanced by suitable design of an algorithm to solve the problem consideration. If processes do not share address space and we could get rid of data dependency among instructions, we can attain higher level of parallelism. The idea of speed up is used as a measure of the speed up which indicates up to what extent to which a sequential program can be parallelized.  Speed up can be taken as a sort of amount of inherent parallelism in a program. In that respect, Amdahl has given a law, called Amdahl's Law, according to this law potential program speedup is stated by the fraction of code (P) which can be parallelised:

Speed up= 1 / 1-p

If no part of the code can be parallelized, P = 0 and speedup = 1 it implies that it is an inherently chronological program. If all the code is parallelized then P = 1, the speedup is infinite. However practically, the code in no program is able to make 100% parallel. Therefore speed up cannot be infinite ever.

If 50% of code can be parallelized, maximum speedup = 2, meaning the code would run twice as fast.  

If we set up the number of processors executing the parallel fraction of work, the relationship can be modeled by:

2485_Potential of Parallelism.png

Where P = parallel fraction, N = total number of processors and S = Serial fraction.The Table 1 shows the values of speed up for various values N and P.

1889_Potential of Parallelism 1.png

The Table 1 proposes that speed up increases as P increases. Though, after a certain limits N doesn't have much impact on the value of speed up. The reason being that is for N processors to remain active, the code must be in some way or other, be divisible in more or less N parts, independent part, every part taking almost equal amount of time.

Posted Date: 7/9/2013 7:16:40 AM | Location : United States







Related Discussions:- Explain potential of parallelism, Assignment Help, Ask Question on Explain potential of parallelism, Get Answer, Expert's Help, Explain potential of parallelism Discussions

Write discussion on Explain potential of parallelism
Your posts are moderated
Related Questions
Hashed strings can often be deciphered by 'brute forcing'. Bad news, eh? Yes, and particularly if your encrypted passwords/usernames are floating around in an unprotected file some

describe the action by thread library to context switch between user level threads

How do subroutines help in program writing? Some of the significant characteristics of Subroutine that help in program writing are: A subroutine is named, each have a

Windows Authentication This provider utilizes the authentication capabilities of IIS. After IIS completes its authentication, ASP.NET uses the authenticated identity's token to

Q. Concurrently read exclusively write? It's one of the models based on PRAM. In this model, processors access the memory location simultaneously for reading whereas exclusivel

Network with point-to-point link is known as (A) Fully Connected Network        (B)  Half Connected Network (C)  Duplex Connected Network    (D)  None of these Ans:

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

How would you implement each in a class design? Ans) A specialized class "is" a specialization of another class and, thus, has the ISA relationship with the other class. An Em

What are the events used for page headers and footers? The events TOP-OF-PAGE and END-OF-PAGE are used for pager headers and footers.

Motherboard is called as motherboard because in the world all borned creature is directly attached to her mother & after it all the relations makes due to her mother so in the simi