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Shenren_CN September 19, 2012 05:30

computational cost of ILU
 
Dear colleagues,

I'm using ILU to precondition a GMRES solver and found that it gets prohibitively expensive to run for a large problem. So I wonder how the computational cost of ILU factorization with 0-fill-ins scales with the dimension/bandwidth of the matrix.

Regards,
Shenren

Shenren_CN September 20, 2012 18:10

I found through literature and some numerical experiments that the computational cost actually scales as N*B, where N is the dimension
of the problem (e.g., computational mesh) and B is the bandwidth.
This is a good property as in parallel code, we want the sequential
code to scale linearly with problem size, thus procs needed increases
only linearly with problem size.

Hope this can be helpful to some people.

Regards,
Shenren

Quote:

Originally Posted by Shenren_CN (Post 382509)
Dear colleagues,

I'm using ILU to precondition a GMRES solver and found that it gets prohibitively expensive to run for a large problem. So I wonder how the computational cost of ILU factorization with 0-fill-ins scales with the dimension/bandwidth of the matrix.

Regards,
Shenren



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