matmul, a C code which compares various methods for computing the matrix product

        A * B = C.

MATMUL can do this for a variety of matrix sizes, and for different arithmetics (real, complex, double precision, integer, even logical!) There are many algorithms built in, including the simple triple DO loop (actually not so simple; there are 6 ways to set it up), some unrolling techniques, and the level 1 and 2 BLAS routines.

MATMUL is interactive, so the user can easily pursue any line of inquiry that seems promising. New algorithms or locally available methods are not to hard to add.


The computer code and data files described and made available on this web page are distributed under the MIT license


matmul is available in a C version and a FORTRAN90 version.

Related Data and Programs:

LINPACK_BENCH, a C code which measures the time needed to factor and solve a linear system.


MEMORY_TEST, a C code which declares and uses a sequence of larger and larger vectors, to see how big a vector can be used on a given machine and compiler.

SUM_MILLION, a C code which sums the integers from 1 to 1,000,000, as a demonstration of how to rate a computer's speed;

TIMER, a C code which demonstrates how to compute CPU time or elapsed time.


  1. John Burkardt, Paul Puglielli,
    Pittsburgh Supercomputing Center,
    MATMUL: An Interactive Matrix Multiplication Benchmark

Source Code:

Last revised on 14 July 2019.