I need often (for i between 0 and 52 * 40 - 1 let's say) to calculate M_i * V_i + F_i where the matrix M_i is of size 2000 * 2000 and is not constant as a function of i, where vectors V_i and F_i are non constant as functions of i. The point is that M_i is either tridiagonal of pentadiagonal (even heptadiagonal) and that F_i as all its coefficients zero except maybe the first and the last.
Naturally I would like to use dgbmv, but due to the special format that M_i has tu be put in to be used with this function, I find it a bit prohibitive.
Do you intel guys have a benchmark of comparisons for lets say case where M_i triangular showing how faster using dgbmv for doing such a product is compared to doing it oneself ?
I could indeed do this test on my computer myself, but more generally, I was wondering is there where benchark documents of this kind, for blas lapack functions for instance ?
Thx in advance,