[petsc-users] Dense multiply Sparse

[Hui Zhang]

I have two matrices A and B stored in sparse format.  While A is really sparse, 
B is relatively
dense (say non-zeros entries about 50%).  Now to multiply the two matrices, 
among 
    
      A*B 
or 
     (B^T * A^T)^T

which is better, or no big difference ?

Thanks!