> On Aug 24, 2016, at 8:07 PM, Harshad Ranadive
> wrote:
>
> Thanks a lot Barry for your help. I have resolved the issue of slow linear
> solver for excessively large RHS vectors to some degree.
>
> To summarize:
>
> 1) In my case, I wanted to solve the same linear system a large number of
Thanks a lot Barry for your help. I have resolved the issue of slow linear
solver for excessively large RHS vectors to some degree.
*To summarize:*
1) In my case, I wanted to solve the *same linear system a large number of
times for different RHS vectors*. Previously I was using the iterative
sol
> On Aug 11, 2016, at 10:14 PM, Harshad Ranadive
> wrote:
>
> Hi Barry,
>
> Thanks for this recommendation.
>
> As you mention, the matrix factorization should be on a single processor.
> If the factored matrix A is available on all processors can I then use
> MatMatSolve(A,B,X) in paralle
Hi Barry,
Thanks for this recommendation.
As you mention, the matrix factorization should be on a single processor.
If the factored matrix A is available on all processors can I then use
MatMatSolve(A,B,X) in parallel? That is could the RHS block matrix 'B' and
solution matrix 'X' be distributed
If it is sequential, which it probably should be, then you can you
MatLUFactorSymbolic(), MatLUFactorNumeric() and MatMatSolve() where you put a
bunch of your right hand side vectors into a dense array; not all million of
them but maybe 10 to 100 at a time.
Barry
> On Aug 10, 2016, at
Effectively utilizing multiple right hand sides with the same system can
result in roughly 2 or at absolute most 3 times improvement in solve time. A
great improvement but when you have a million right hand sides not a giant
improvement.
The first step is to get the best (most efficient
On Wed, Aug 10, 2016 at 9:54 PM, Harshad Ranadive wrote:
> Hi All,
>
> I have currently added the PETSc library with our CFD solver.
>
> In this I need to use KSPSolve(...) multiple time for the same matrix A. I
> have read that PETSc does not support passing multiple RHS vectors in the
> form of
Hi All,
I have currently added the PETSc library with our CFD solver.
In this I need to use KSPSolve(...) multiple time for the same matrix A. I
have read that PETSc does not support passing multiple RHS vectors in the
form of a matrix and the only solution to this is calling KSPSolve multiple
ti
