On Sat, Aug 27, 2011 at 17:09, Likun Tan <likunt at andrew.cmu.edu> wrote:
> Another question is, if the size is small in x and y directions, and large > in z direction, i want more of processors, but the number is restricted to > the size in x and y direction, since partition is not allowed in z > direction, any way to improve efficiency? > This is a fundamental problem. If there is tight coupling in the z direction, then it is algorithmically good to keep it on a single process, but it is not good for parallel scalability because you are not allowed to decompose in that direction. You can write a new integral function with the z direction decomposed, but it's significantly more complicated. The practical solution is usually to not decompose in z and pay the price of somewhat reduced parallel scalability in exchange for simplicity, algorithmic performance, and efficiency. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110827/80fb3bbe/attachment.htm>
