armadillo linear system solver (with openblas)

Question

I\'ve been testing various open source codes for solving a linear system of equations in C++. So far the fastest I\'ve found is armadillo, using the OPENblas package as well

Answer 1

Armadillo doesn't prevent OpenBlas from using more cores. It's possible that the current implementation of OpenBlas simply chooses 2 cores for certain operations.

You can see Armadillo's source code directly in the downloadable package (it's open source), in the folder "include". Specifically, have a look at the file "include/armadillo_bits/fn_solve.hpp" (which contains the user accessible solve() function), and the file "include/armadillo_bits/auxlib_meat.hpp" (which contains the wrapper and housekeeping code for calling the torturous Blas and Lapack functions).

If you already have Armadillo installed on your machine, have a look at "/usr/include/armadillo_bits" or "/usr/local/include/armadillo_bits".