Re: [petsc-users] Memory optimization

2019-12-10 Thread Jose E. Roman
I guess conditioning is getting worse. I would try using MUMPS for the sub_pc LU. Jose > El 10 dic 2019, a las 18:36, Perceval Desforges > escribió: > > Hello again, > > I have tried following your advice to use preconditioned iterative solvers > for my 3D systems, and have been

Re: [petsc-users] Memory optimization

2019-12-10 Thread Perceval Desforges
Hello again, I have tried following your advice to use preconditioned iterative solvers for my 3D systems, and have been encountering some difficulties. I have been following the recommendations of section 3.4.1 of the slepc user's manual, setting the following options: -st_ksp_type gmres

Re: [petsc-users] Memory optimization

2019-11-26 Thread Smith, Barry F.
> I am basically trying to solve a finite element problem, which is why in 3D I > have 7 non-zero diagonals that are quite farm apart from one another. In 2D I > only have 5 non-zero diagonals that are less far apart. So is it normal that > the set up time is around 400 times greater in the 3D

Re: [petsc-users] Memory optimization

2019-11-26 Thread Perceval Desforges
Hello, This is the output of -log_view. I selected what I thought were the important parts. I don't know if this is the best format to send the logs. If a text file is better let me know. Thanks again, -- PETSc Performance Summary:

Re: [petsc-users] Memory optimization

2019-11-25 Thread Matthew Knepley
On Mon, Nov 25, 2019 at 11:45 AM Perceval Desforges < perceval.desfor...@polytechnique.edu> wrote: > I am basically trying to solve a finite element problem, which is why in > 3D I have 7 non-zero diagonals that are quite farm apart from one another. > In 2D I only have 5 non-zero diagonals that

Re: [petsc-users] Memory optimization

2019-11-25 Thread Jose E. Roman
In 3D problems it is recommended to use preconditioned iterative solvers. Unfortunately the spectrum slicing technique requires the full factorization (because it uses matrix inertia). > El 25 nov 2019, a las 18:44, Perceval Desforges > escribió: > > I am basically trying to solve a finite

Re: [petsc-users] Memory optimization

2019-11-25 Thread Perceval Desforges
I am basically trying to solve a finite element problem, which is why in 3D I have 7 non-zero diagonals that are quite farm apart from one another. In 2D I only have 5 non-zero diagonals that are less far apart. So is it normal that the set up time is around 400 times greater in the 3D case? Is

Re: [petsc-users] Memory optimization

2019-11-25 Thread Jose E. Roman
Probably it is not a preallocation issue, as it shows "total number of mallocs used during MatSetValues calls =0". Adding new diagonals may increase fill-in a lot, if the new diagonals are displaced with respect to the other ones. The partitions option is intended for running several nodes. If

Re: [petsc-users] Memory optimization

2019-11-25 Thread Matthew Knepley
On Mon, Nov 25, 2019 at 11:20 AM Perceval Desforges < perceval.desfor...@polytechnique.edu> wrote: > Hi, > > So I'm loading two matrices from files, both 100 by 1000. I ran > the program with -mat_view::ascii_info and I got: > > Mat Object: 1 MPI processes > type: seqaij >

Re: [petsc-users] Memory optimization

2019-11-25 Thread Perceval Desforges
Hi, So I'm loading two matrices from files, both 100 by 1000. I ran the program with -mat_view::ascii_info and I got: Mat Object: 1 MPI processes type: seqaij rows=100, cols=100 total: nonzeros=700, allocated nonzeros=700 total number of mallocs used during

Re: [petsc-users] Memory optimization

2019-11-25 Thread Jose E. Roman
Then I guess it is the factorization that is failing. How many nonzero entries do you have? Run with -mat_view ::ascii_info Jose > El 22 nov 2019, a las 19:56, Perceval Desforges > escribió: > > Hi, > > Thanks for your answer. I tried looking at the inertias before solving, but > the

Re: [petsc-users] Memory optimization

2019-11-22 Thread Perceval Desforges
Hi, Thanks for your answer. I tried looking at the inertias before solving, but the problem is that the program crashes when I call EPSSetUp with this error: slurmstepd: error: Step 2140.0 exceeded virtual memory limit (313526508 > 107317760), being killed I get this error even when there

Re: [petsc-users] Memory optimization

2019-11-21 Thread Jose E. Roman via petsc-users
Don't use -mat_mumps_icntl_14 to reduce the memory used by MUMPS. Most likely the problem is that the interval you gave is too large and contains too many eigenvalues (SLEPc needs to allocate at least one vector per each eigenvalue). You can count the eigenvalues in the interval with the

[petsc-users] Memory optimization

2019-11-21 Thread Perceval Desforges via petsc-users
Hello all, I am trying to obtain all the eigenvalues in a certain interval for a fairly large matrix (100 * 100). I therefore use the spectrum slicing method detailed in section 3.4.5 of the manual. The calculations are run on a processor with 20 cores and 96 Go of RAM. The options I