Question

Needing help with Operating Systems questions please, I thank you in advance

Use the code below to answer the following questions:

for(int x = 0; x < 20; x++)
    z(x) = a(x) + b(x);

If a system contains(1) processor, how many steps are required to perform the code above?

If a system contains (5) parallel processors, how many steps are required to perform the code above?

If a system contains (10) parallel processors, how many steps are required to perform the code above?

Answer 1

The above is an example of data parallelism.

For the given 'for loop' to complete 20 iterations are needed, as x begins at 0 and ends at 19.

If a system contains (1) processor,20 iterations will be performed on the same processor.

If a system contains (5) processors, 20 iterations will be split is 5 parts. Each processor will perform 4 iterations simultaneously.

If a system contains (10) processors, 20 iterations will be split is 10 parts. Each processor will perform 2 iterations simultaneously.

Therefore, irrepective of the number of processors, the steps required to perform the code above is 20.

Parallel processing helps in reducing the execution time and not step reduction.