A fairly fast c based prime calculator. Calculates in parallel & sequentially
Makes use of OpenMPI to assist in paralell computation
It takes into account the cache size of the CPU it is calculating, showing vast improvments to calculation speed. It estimates the cachline of the cpu.
For running on Linux the following is required to be installed before execution: sudo apt update
sudo apt install build-essential
sudo apt-get install --reinstall openmpi-bin libopenmpi-dev
Compile by typing make in bash and running the resultant a.out
As this supports OpenMPI it can be executed like:
mpiexec a.out -s 2 -c -v 1 -n 100
Take note that the OpenMPI implementation is not complete and does not calculate primes correctly at present.
it supports elementary command line input eg:
-N = Max value of Primes to test to factor. 1 = MAX_INT, 2 = 2*MAX_INT etc
-V = Toggle verbose mode
-S = a value [1-3] that changes how the primes are tested & calculated. 1->Default; 2->Most optimizations used; 3->Some experimental options enabled.
-C to estimate the L2 cache of the system and use it effeciently -NB option for speed