Re: [petsc-users] Best practices for solving Dense Linear systems

Indeed - I was just using the default solver (GMRES with ILU). Using just standard LU (direct solve with "-pc_type lu -ksp_type preonly"), I find elemental to be extremely slow even for a 1000x1000 matrix. For MPIaij it's throwing me an error if I tried "-pc_type lu". I'm attaching the code he

Re: [petsc-users] Best practices for solving Dense Linear systems

What is the output of -ksp_view for the two case? It is not only the matrix format but also the matrix solver that matters. For example if you are using an iterative solver the elemental format won't be faster, you should use the PETSc MPIDENSE format. The elemental format is really inten

Re: [petsc-users] Best practices for solving Dense Linear systems

Thank you for the response. I've just been running some tests with matrices up to 2e4 dimensions (dense). When I compared the solution times for "-mat_type elemental" and "-mat_type mpiaij" running with 4 cores, I found the mpidense versions running way faster than elemental. I have not been ab

Re: [petsc-users] Best practices for solving Dense Linear systems

> On Aug 6, 2020, at 7:32 PM, Nidish wrote: > > I'm relatively new to PETSc, and my applications involve (for the most part) > dense matrix solves. > > I read in the documentation that this is an area PETSc does not specialize in > but instead recommends external libraries such as Elemental

Re: [petsc-users] Test convergence with non linear preconditioners

On Thu, Aug 6, 2020 at 10:08 PM Adolfo Rodriguez wrote: > Considering the output produced by snes_view (attachment), would be > possible to change the linear solver tolerances and the preconditioning > level or type? > Yes. The options prefix is shown for each subsolver. For example, you can cha

Re: [petsc-users] Test convergence with non linear preconditioners

Considering the output produced by snes_view (attachment), would be possible to change the linear solver tolerances and the preconditioning level or type? Adolfo Virus-free.

[petsc-users] Best practices for solving Dense Linear systems

I'm relatively new to PETSc, and my applications involve (for the most part) dense matrix solves. I read in the documentation that this is an area PETSc does not specialize in but instead recommends external libraries such as Elemental. I'm wondering if there are any "best" practices in this

Re: [petsc-users] Code (possibly) not running on GPU with CUDA

I do not have DMSetFromOptions in the code, so this may well be the issue --- Dr Gordon P S Gibb EPCC, The University of Edinburgh Tel: +44 131 651 3459 On 5 Aug 2020, at 18:48, Barry Smith mailto:bsm...@petsc.dev>> wrote: Gordon, Do you have