Ok, thanks. In fact, I have another major problem: when running on multi-GPU with PETSc my results are totally inconsistent compared to a single GPU .
In my code, for now, I'm assuming a 1-1 correspondence between CPU and GPU: I run on 8 cores and 8 GPUs (4 K10). How can I enforce this in the PETSc solver? Is it automatically done or do I have to specify some options? Thanks again Andrea On Jan 17, 2014, at 8:48 PM, Matthew Knepley <[email protected]> wrote: > On Fri, Jan 17, 2014 at 1:29 PM, Andrea Lani <[email protected]> wrote: > Dear Devs, > > is the PCBJACOBI solver fully ported to GPU in the latest petsc-dev version? > if not, is there any intention to do so in the near future? > > I have a convection-dominated (with strong discontinuities in the flow field) > MHD problem where PCASM and PCBJACOBI both work fine with KSPGMRES. > > These can be done on the GPU, but the key is the inner PC. Right now, we have > no ILU0 or equivalent, which I think is what > you want. You can try the AMG variants, but I am guessing they would not be > great for convection dominated flow. > > Maybe Karl has a better suggestion? > > Thanks, > > Matt > > Looking for a speedup in my code (which is using a petsc-dev version about > two-months old), the only GPU alternative I found was PCJACOBI. This is > indeed considerably faster on GPU, but does not converge (neither does, > consistently, its CPU counterpart) if not for a few iterations before blowing > up. Any other alternative for GPU-based preconditioners or solvers worth > trying at the moment? > > Thanks in advance for your advice > > Andrea > > > > -- > Dr. Andrea Lani > Senior Research Engineer, PhD > Aeronautics & Aerospace dept., CFD group > Von Karman Institute for Fluid Dynamics > Chausse de Waterloo 72, > B-1640, Rhode-Saint-Genese, Belgium > fax : +32-2-3599600 > work : +32-2-3599769 > [email protected] > > > > -- > What most experimenters take for granted before they begin their experiments > is infinitely more interesting than any results to which their experiments > lead. > -- Norbert Wiener
