Choose iterative Solver type PCG because of insufficient RAM for direct solver with Sparse matrix

- June 15, 2019 at 10:46 am
  
  Johnson
  Subscriber
  
  Hi all,
  
  the solver for my project (1Mio DOFs) is using the direct Sparse Matrix solver. But I have limited RAM and he is always going into out-core memory mode regarding to the solution output.
  
  Therefore I changed the Solver type to iterative and put the EQSLV, PCG command under the Static Structural branch.
  
  But the Programm is still choosing the direct solver running into the same problem.
  
  BCSOPT,,INCORE does not change anything either...
  
  Why is my change being ignored?
  
  Would very much appreciate your help!
- June 15, 2019 at 11:08 am
  
  peteroznewman
  Subscriber
  
  You have something in your model that is not supported by the PCG solver. If you scan your Solve.out file, it will give you more detail about what that is. I can't recall exactly but maybe Joints?
- June 15, 2019 at 12:55 pm
  
  Johnson
  Subscriber
  
  Thanks!
  
  I found something. Its says:
  
  The preconditioned conjugate gradient solver (EQSLV,PCG command) is
  only available for single-field thermal analyses with unsymmetric
  matrices. The solver has been reset to SPARSE.
  
  I am doing a static structural analysis. Can I still use a iterative solver?
  
  Unfortunately I do not habe enough RAM to use SPARSE.