  We investigate effects of ordering in blocked matrix--matrix multiplication.
We find that submatrices do not have to be stored contiguously in memory to
achieve near optimal performance. Instead it is the choice of execution order
of the submatrix multiplications that leads to a speedup of up to four times
for small block sizes. This is in contrast to results for single matrix
elements showing that contiguous memory allocation quickly becomes irrelevant
as the blocksize increases.
