https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Subdividing-BLACS-grid/m-p/1149786#M27018 <P>I am trying to use Scalapack to calculate the eigenvalues of a large matrix using the <A href="https://software.intel.com/en-us/mkl-developer-reference-fortran-p-heevd">pzheevd</A>. If I use all processes to calculate a single matrix everything seems to work fine. But i would like to calculate different matrices in parallel:</P> <P>Say I have 32 processes then I'd divide it into a 32 = 4 x 8 grid. Where I distribute my matrices across 4 processes and then calculate 8&nbsp;matrices in parallel.</P> <P>I tried to do this using MPI_Comm_split, but I realized that Scalapack doesn't use a communicator provided by the user. Instead it uses BLACS grids. How can I distribute my Scalapack matrices such that I have parallelism between matrices as well as within one matrix?</P> <P>I couldn't find any examples and I couldn't understand how the BLACS grid is divided. Could you tell me some decent resources? Are there any alternative libraries that rely on MPI rather than PVM?</P> Tue, 31 Oct 2017 20:46:12 GMT Matthias_R_ 2017-10-31T20:46:12Z https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Subdividing-BLACS-grid/m-p/1149786#M27018 <P>I am trying to use Scalapack to calculate the eigenvalues of a large matrix using the <A href="https://software.intel.com/en-us/mkl-developer-reference-fortran-p-heevd">pzheevd</A>. If I use all processes to calculate a single matrix everything seems to work fine. But i would like to calculate different matrices in parallel:</P> <P>Say I have 32 processes then I'd divide it into a 32 = 4 x 8 grid. Where I distribute my matrices across 4 processes and then calculate 8&nbsp;matrices in parallel.</P> <P>I tried to do this using MPI_Comm_split, but I realized that Scalapack doesn't use a communicator provided by the user. Instead it uses BLACS grids. How can I distribute my Scalapack matrices such that I have parallelism between matrices as well as within one matrix?</P> <P>I couldn't find any examples and I couldn't understand how the BLACS grid is divided. Could you tell me some decent resources? Are there any alternative libraries that rely on MPI rather than PVM?</P> Tue, 31 Oct 2017 20:46:12 GMT https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Subdividing-BLACS-grid/m-p/1149786#M27018 Matthias_R_ 2017-10-31T20:46:12Z