# Calculix solver breaks/terminates without an error with models larger 250k elements

**URL:** <https://calculix.discourse.group/t/calculix-solver-breaks-terminates-without-an-error-with-models-larger-250k-elements/1958>\
**Category:** Uncategorized\
**Created:** [December 8, 2023, 2:27pm UTC](https://calculix.discourse.group/t/calculix-solver-breaks-terminates-without-an-error-with-models-larger-250k-elements/1958 "2023-12-08T14:27:43Z")\
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**Author:** ![loopluc](https://avatars.discourse-cdn.com/v4/letter/l/b3f665/32.png) [@loopluc](https://calculix.discourse.group/u/loopluc)\
**Post date:** [December 11, 2023, 8:26am UTC](https://calculix.discourse.group/t/calculix-solver-breaks-terminates-without-an-error-with-models-larger-250k-elements/1958/13 "2023-12-11T08:26:32Z")

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Thank you all for your help!

Lucas and Lucas investigated and found:

- The main problem seems to be the factorization step. However, the matrix is simply too large for the PastiX solver to handle. Preallocation of the memory seems to be to large.  
As written above I already had this concern and tested with the other solvers.  
**BUT i always used ccx\_static. With ccx\_dynamic it works when using PARDISO** 🙂  
(tested with CaculiX 2.20. and 2.21)

With a bit more of search i could have found this post:

> [@Problem with Large Model Solution](https://calculix.discourse.group/t/problem-with-large-model-solution/748/44):
>
> that’s correct on ccx\_static.exe. it won’t run pardiso. only the ccx\_dynamic.exe file will. to switch between compilers you need to reference the ccx manual. in the inp file i provided, look for the following line near the bottom of the file: \*STATIC,SOLVER=PARDISO you can either remove the SOLVER= option (that should default to PASTIX) or you can explicitly call one of three solvers: \*STATIC \*STATIC,SOLVER=PASTIX \*STATIC,SOLVER=PARDISO \*STATIC,SOLVER=SPOOLES unfortunately, there doesn’t…

Anyway it runs with ccx\_dynamic and Pardiso solver:

> Decascading the MPC’s
> 
> Determining the structure of the matrix:  
> Using up to 16 cpu(s) for setting up the structure of the matrix.  
> number of equations  
> 1910259  
> number of nonzero lower triangular matrix elements  
> 95283540
> 
> Using up to 16 cpu(s) for the stress calculation.
> 
> Using up to 16 cpu(s) for the symmetric stiffness/mass contributions.
> 
> Factoring the system of equations using the symmetric pardiso solver  
> number of threads = 16
> 
> Using up to 16 cpu(s) for the stress calculation.
> 
> Job finished
> 
> * * *
> 
> Total CalculiX Time: 693.189322

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