Introduction to Parallel ProcessingCh. 12, Pg. 514-526.ppt

Introduction to Parallel ProcessingCh. 12, Pg. 514-526 CS147 Louis Huie Topics Covered An Overview of Parallel Processing Parallelism in Uniprocessor Systems Organization of Multiprocessor Flynn’s Classification System Topologies MIMD System Architectures An Overview of Parallel Processing What is parallel processing? Parallel processing is a method to improve computer system performance by executing two or more instructions simultaneously. The goals of parallel processing. One goal is to reduce the “wall-clock” time or the amount of real time that you need to wait for a problem to be solved. Another goal is to solve bigger problems that might not fit in the limited memory of a single CPU. An Analogy of Parallelism The task of ordering a shuffled deck of cards by suit and then by rank can be done faster if the task is carried out by two or more people. By splitting up the decks and performing the instructions simultaneously, then at the end combining the partial solutions you have performed parallel processing. Another Analogy of Parallelism Another analogy is having several students grade quizzes simultaneously. Quizzes are distributed to a few students and different problems are graded by each student at the same time. After they are completed, the graded quizzes are then gathered and the scores are recorded. Parallelism in Uniprocessor Systems It is possible to achieve parallelism with a uniprocessor system. Some examples are the instruction pipeline, arithmetic pipeline, I/O processor. Note that a system that performs different operations on the same instruction is not considered parallel. Only if the system processes two different instructions simultaneously can it be considered parallel. Parallelism in a Uniprocessor System A reconfigurable arithmetic pipeline is an example of parallelism in a uniprocessor system. Each stage of a reconfigurable arithmetic pipeline has a multiplexer at its input. The multipl