[petsc-users] Why the convergence is much slower when I use two nodes

[Ji Zhang]

Dear all,

I'm a PETSc user. I'm using GMRES method to solve some linear equations.
I'm using boundary element method, so the matrix type is dense (or
mpidense). I'm using MPICH2, I found that the convergence is fast if I only
use one computer node; and much more slower if I use two or more nodes. I'm
interested in why this happen, and how can I improve the convergence
performance when I use multi-nodes.

Thanks a lot.

此致
    敬礼
张骥（博士研究生）
北京计算科学研究中心
北京市海淀区西北旺东路10号院东区9号楼 （100193）

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
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