What pressure solver is OpenFOAM using? Are you using the same convergence tolerance for the pressure solver for the two approaches? Have you tried PETSc with a simpler solver: -pc_type bjacobi or -pc_type asm ; the problem is pretty small and maybe at this size hypre is overkill?
Barry > On Sep 13, 2018, at 12:58 PM, Edoardo alinovi <[email protected]> > wrote: > > Hello PETSc's frieds, > > It is a couple of weeks that I am trying to enhance the perforamance of my > code. Actually I am solving NS equation for a 3D problem of 220k cells with > 4procs on my laptop (i7-7800k @ 2.3Ghz with dynamic overclocking). I have > installed petsc under linux suse 15 in a virtual machine (I do not know if > this is important or not). > > After some profiling, I can see that the bottle neck is inside KSPSolve > while solving pressure equation (solved with cg + hypre pc). For this reason > my code is running twice time slower than openFOAM and the gap is only due > the solution of pressure. Have you got some hints for me? At this point I am > sure I am doing something wrong! I have attached the log of a test simulation. > > Thank you very much! > > ------ > > Edoardo Alinovi, Ph.D. > > DICCA, Scuola Politecnica > Universita' di Genova > 1, via Montallegro > 16145 Genova, Italy > > email: [email protected] > Tel: +39 010 353 2540 > > > <run_log_view.txt>
