Sorry for the late response. In 3.0.0, some things have changed in ASM. Now ASM try to make a "smart" subdomain partitioning, they are likely to improve things in the case of unstructured grid problems or many subdomanins per processor. However, if your problem is on a structured grid, and you are using 2 processors, and let say 4 subdomains (i.e., 2 subdoms/proc), then in that particular case the new "smart" partitioning could be a bit worse than the one obtained with the old code. But I would not expect a dramatic difference in the GMRES iteration counts...
The differences will only show-up if you built PETSc with ParMETIS and you are using more than 1 subdomain per processor. Is this your case? On Sun, Jan 25, 2009 at 3:35 PM, Billy Ara?jo <billy at dem.uminho.pt> wrote: > > I compiled my code using the new version of PETSc but the convergence of the > GMRES has suffered greatly, specially in parallel. I am using GMRES with ASM > preconditioner. > Has there been any change? > > Billy. -- Lisandro Dalc?n --------------- Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) PTLC - G?emes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594
