CPS 5401 Fall 2015
In-class Activity
October 20 Class
Name ___________________________________
Introduction to Parallel Computing
We will work through the LLNL Introduction to Parallel Computing tutorial at
https://computing.llnl.gov/tutorials/parallel_comp/ using the Stampede
supercomputer at Texas Advanced Computing Center. You will also need to refer to
the Stampede User Guide at https://portal.tacc.utexas.edu/user-guides/stampede .
1. Login to your Stampede account.
2. Read the Overview section of the tutorial. Give four reasons why we need to learn
and use parallel computing.
3. Read the Concepts and Terminology section of the tutorial.
a. Read the System Overview section of the Stampede User Guide. Which
category (ies) of Flynn’s Classical Taxonomy of parallel computers are applicable
to Stampede?
b. Amdahl’s Law problem: Suppose you are able to parallelize 80% of a code in
terms of its serial execution time.
1) What is the maximum speedup you can obtain using 16 processors?
2) What is the maximum speedup you can obtain using an infinite number of
processors?
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4. Read the section of the tutorial on Parallel Computer Memory Architectures.
Describe the parallel computer memory architecture of Stampede and draw a
diagram to illustrate it.
5. Read the section of the tutorial on Parallel Programming Models. What parallel
programming models are supported on Stampede?
6. Read the subsection on the Pi Calculation in the Parallel Examples section of the
tutorial. Follow the directions in the Stampede User Guide to compile and run both
the C and Fortran example codes.
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