petsc-3.10.5 2019-03-28
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# KSPGROPPCG

A pipelined conjugate gradient method from Bill Gropp This method has two reductions, one of which is overlapped with the matrix-vector product and one of which is overlapped with the preconditioner.

See also KSPPIPECG, which has only a single reduction that overlaps both the matrix-vector product and the preconditioner.

### Notes

MPI configuration may be necessary for reductions to make asynchronous progress, which is important for performance of pipelined methods. See the FAQ on the PETSc website for details.

### Contributed by

Pieter Ghysels, Universiteit Antwerpen, Intel Exascience lab Flanders

### Reference

http://www.cs.uiuc.edu/~wgropp/bib/talks/tdata/2012/icerm.pdf

### See Also

KSPCreate(), KSPSetType(), KSPPIPECG, KSPPIPECR, KSPPGMRES, KSPCG, KSPCGUseSingleReduction()

### Level

intermediate

### Location

src/ksp/ksp/impls/cg/groppcg/groppcg.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages