So was mucking around today so thought I would try this out as came across it.

If you are able and know how to run this python script and see what the outcome is.

Its currently set to getting prime numbers within the first 200k

Here is my result on my unraid server AMD 3900X

root@6cd0543b9bc2:/# python3 prime2.py
Find all primes up to: 200000 using 96 processes.
Time elapsed: 72.67 seconds
Number of primes found 17984

import multiprocessing as mp
import time

 

#max number to look up to
max_number = 200000
#four processes per cpu
num_processes = mp.cpu_count() * 4

 

def chunks(seq, chunks):
        size = len(seq)
        start = 0
        for i in range(1, chunks + 1):
            stop = i * size // chunks
            yield seq[start:stop]
            start = stop

 

def calc_primes(numbers):
    num_primes = 0
    primes = []

 

    #Loop through each number, then through the factors to identify prime numbers
    for candidate_number in numbers:
        found_prime = True
        for div_number in range(2, candidate_number):
            if candidate_number % div_number == 0:
                found_prime = False
                break
        if found_prime:
            primes.append(candidate_number)
            num_primes += 1
    return  num_primes

 

def main():
    #Record the test start time
    start = time.time()
    pool = mp.Pool(num_processes)
    #0 and 1 are not primes
    parts = chunks(range(2, max_number, 1), num_processes)
    #run the calculation
    results = pool.map(calc_primes, parts)
    total_primes = sum(results)
    pool.close()
    #Once all numbers have been searched, stop the timer
    end = round(time.time() - start, 2)
    #Display the results, uncomment the last to list the prime numbers found
    print('Find all primes up to: ' + str(max_number) + ' using ' + str(num_processes) + ' processes.')
    print('Time elapsed: ' + str(end) + ' seconds')
    print('Number of primes found ' + str(total_primes))
if __name__ == "__main__":
    main()