[petsc-users] Storage space for symmetric (SBAIJ) matrix

[Jed Brown]

On Tue, Sep 21, 2010 at 21:20, Daniel Langr <daniel.langr at gmail.com> wrote:
> Certainly true, but the time for computing matrix elements will take much
> more time than the assembly process. To say truth we don't know yet how
> much, because new method for computing Hamiltonian are still being
> developed. Within competing methods this takes about 20 to 30 percent of the
> time of the iterative eigensolver run, which is not neglectable. If not
> stored, the elements would need to be evaluated multiple times.

I can't guarantee it for your particular problem, but it is
exceedingly rare that loading the matrix from disk is cheaper than
recomputing it.

Jed