Is the number of iterations to convergence also increasing with the number of processors?
A couple of possibly relevant FAQs: http://www.mcs.anl.gov/petsc/documentation/faq.html#differentiterations http://www.mcs.anl.gov/petsc/documentation/faq.html#slowerparallel On Thu, Sep 29, 2016 at 10:56 AM, Ji Zhang <[email protected]> wrote: > Dear all, > I'm using KSP included in PETSc to solve some linear equations. The code > runs well if I do not use mpirun. However, the running duration since > increase linearly with the number of CUPs. > > The solve method is gmres and without precondition method. For a same case, > it need about 4.9s with 'mpirun -n 1', which is about 7.9s if I use 'mpirun > -n 2', and 12.5s when I use 'mpirun -n 4'. It looks like that I need double > time when I use double CUPs. Is there any one could give me some suggestion? > Thanks. > > Best, > Regards, > Zhang Ji, PhD student > Beijing Computational Science Research Center > Zhongguancun Software Park II, No. 10 Dongbeiwang West Road, Haidian > District, Beijing 100193, China
