PHYS 27/193: Homework 1

You can answer the questions in a Word or Text document, which you should then email to me as an attachment.

1. On the Introduction Page, under Scientific Computing, there are a number of scientific or mathematical types of activities you might do in a scientific environment; these are listed in blue

   For each item, give a simple concrete example of the activity.

   Note that you may well have to do a little research on some of these (either on the web or in the library)!
   For example, for statistics, the first item, you might write something like this:

   
   Statistics

   Suppose one has taken data from an experiment and wants to characterize
   the properties of these measurements. Doing "statistics" involves
   computing things like:
   
    
   the "mean" value, 
    
   the "standard deviation", 
    
   the "relative errors", 
    
   and "correlations"
    
   associated with the measurements.
   
   These measurements are necessary so that we can understand how
   accurate the experiment was, and whether the measurements support
   various theories.
   

   
   

   
   

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2. Below are links to three supercomputing centers. At there centers are several large computing "resources" (where I have or am now running simulations)

   NERSC The National Energy Research Supercomputing Center
   SDSC The San Diego Supercomputing Center
   PSU The Pittsburgh Supercomputing Center

   Explore! the websites of these facilities.

   Choose the following machines at each of the centers:

   • NERSC: Franklin
   • SDSC: Datastar
   • PSC: BigBen
   report the following:
   • How many CPU processors does the computer have (conut a "core" as a CPU)?
   • How much total memory does the computer have?
   • What Operating System does each use?

   At each center, there is a large Archival disk system (called HPSS, FAR, or other names) which is for storing results of large computations.

   • How much total disk space does the center provide for storage?

   
   

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3. The speed of a supercomputer is usually reported in "giga or teraFLOPS" (one FLOP = 1 floating point operation/second). A floating point operation is a multiplication or division of two real numbers.

   How many multiplications can a 100 Teraflop computer perform in 1 year, running continuously?

   What is the top speed of the computers above?

   How many times bigger than your (or a friend's) PC is the center's:

   • memory
   • disk space
   • numerical processing power (speed)^*

   * The computing speed (in FLOPS) of a modern single CPU PC is very roughly about 50% of the speed of the CPU (it depends on what you are computing). Thus if you have a 1.6 GHz CPU, your machine can do about 0.8 GFlops (GigaFlops), or 0.8 * 10⁹ = 800 million floating point operations per second).