[petsc-users] Increasing nodes doesn't decrease memory per node.

[Jose E. Roman]

> El 31/8/2015, a las 21:50, Hank Lamm <hanklammiv at gmail.com> escribió:
> 
> If I use MatView to check the type of my matrix, it replies mpiaij, not seqaij.  Am I correct in understanding your comments to mean that the reason for the error that when I do the spectrum slicing, it is creating seqaij for each processor?

It is creating a seqaij matrix if partitions=size. The more partitions the more memory per node you need. I presume with partitions=size there is not enough memory to store the copy of the matrix plus the factorized matrix. Use of multiple communicators is explained in section 3.4.5 of SLEPc users guide, including the use of MUMPS.

Jose