HelloMP

A modification of the HelloMP parallelization by Prof. J.Behrens.

Finding the primes between 2 and a big number by using parallelization

Description and Purpose

This O(1)-line code demonstrates parallelization with OpenMP OMP_NUM_THREADS represent the number of processors. For this project, I have worked on my personal computer, with 7 processors, and the university's GPU server with 16 processors(OMP_NUM_THREADS).

Contents of this Project

README    - this file
Makefile  - Makefile tested for macOS
Hello.c   - parallelized "Hello World" C-program and an algorithm to check whether a number is prime or not by dividing the range
            to the number of processors available.

What do do here

First, build the executable by typing

%> make

If this fails, you have to adjust your path and settings, however, I don't know how...

Second, set up the number of threads (e.g. to four)

%> export OMP_NUM_THREADS=4

Third, run the program

%> Hello

Result

For the prime numbers between 2 and 800,000:

    2:36 Seconds for seriel only(with out parallelization)
    1:16 seconds for 7 processors personall computer
    55 seconds for 16 processors(Uni-server)

Framework for code, directly copied from

(c) 2021, Jörn Behrens (joern.behrens@uni-hamburg.de)

Added work by:

(c) 2021, Dawit Hailu (dawit.hailu@uni-hamburg.de)