# Solver for large models **URL:** \ **Category:** General Questions\ **Created:** [January 4, 2023, 1:00pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660 "2023-01-04T13:00:03Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 4, 2023, 1:00pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/1 "2023-01-04T13:00:03Z")
Could anybody prepare complete kit of solvers for PPM/ Calculix to solve large problems . So far I have used several variants of 2.19 and 2.20 for windows os without success . I stiil can not resolve model with 4,5 milion of nodes even using Iterative solvers (error in u\_realloc: allallocating memory) I have also searched in calculix forum and found dynamici8.exe but it also doesn’t work best regards ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [January 4, 2023, 1:06pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/2 "2023-01-04T13:06:47Z")
The most complete package for ccx 0.20 can be found here: [PrePoMax](http://www.tu.kielce.pl/~rokach/instr/ppm_main.htm) If this (especially Pardiso) doesn’t work then it’s unlikely that any other (especially older) version will work. I think that it would be better to keep this discussion on the CalculiX forum. There it’s much more likely that someone will help with your problems related purely to the solver. ---
**Author:** ![SergioP1975](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/sergiop1975/32/37_2.png) [@SergioP1975](https://prepomax.discourse.group/u/SergioP1975)\ **Post date:** [January 4, 2023, 1:48pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/3 "2023-01-04T13:48:14Z")
Do you really need a model with 4.5 million of nodes? ---
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 4, 2023, 2:05pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/4 "2023-01-04T14:05:16Z")
It will be very hard to reduce model. Similar model was calculated in Creo simulate but this is completely different software( also calculated as solid ,not shell ) . ![image001.jpg](https://global.discourse-cdn.com/free1/uploads/prepomax/original/1X/77d4802b415306da2301d22bf581a5991b958375.jpeg) ![image003.jpg](https://global.discourse-cdn.com/free1/uploads/prepomax/original/1X/1d9e0fbc9dee02b77e19979e95918b3f8075be66.jpeg) ---
**Author:** ![SergioP1975](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/sergiop1975/32/37_2.png) [@SergioP1975](https://prepomax.discourse.group/u/SergioP1975)\ **Post date:** [January 4, 2023, 2:34pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/5 "2023-01-04T14:34:41Z")
Sometimes one has to “invest” some time simplifying the CAD (remove small features, holes…), or the FEA model (swithing to shell or beams models, replacing contacts with TIE or fusionating bodies in CAD) in order to have a model that can be solved in a razonable time with the available resources (soft, hard, human time…) ---
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 4, 2023, 4:48pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/6 "2023-01-04T16:48:20Z")
this model is totally simplified in my opinion (exept of shells). In real this structure has ca 65 ton weight and ca 40 m lenght ---
**Author:** ![SergioP1975](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/sergiop1975/32/37_2.png) [@SergioP1975](https://prepomax.discourse.group/u/SergioP1975)\ **Post date:** [January 4, 2023, 5:21pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/7 "2023-01-04T17:21:05Z")
Then probably you should consider using shell and beam elements, maybe even using other solver as Mecway that allow you to work with different kind of beams and real shells. ---
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 5, 2023, 12:44pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/8 "2023-01-05T12:44:19Z")
I have made sample as one solid - cuboid , then meshed with solid elements . I have obtained over 3 million elements and over 4,249 million nodes , next step was adding material properties bonduary conditions applied forces . Finally model was solved without any problems . I assume that solver is not problem. What you think ? ---
**Author:** ![Kuhl](https://avatars.discourse-cdn.com/v4/letter/k/e0b2c6/32.png) [@Kuhl](https://prepomax.discourse.group/u/Kuhl)\ **Post date:** [January 5, 2023, 3:04pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/9 "2023-01-05T15:04:53Z")
I think (not quite sure if I remember correctly) allocation of necessary memory for computation is based on the highest node number in the model. If you add a single node with a very high number, you might get that error, even for small models. So If the node numbering of your model is not continious, you might have some very high node numbers that cause the problem. Maybe there ist a way to renumber all nodes? ---
**Author:** ![Kuhl](https://avatars.discourse-cdn.com/v4/letter/k/e0b2c6/32.png) [@Kuhl](https://prepomax.discourse.group/u/Kuhl)\ **Post date:** [January 5, 2023, 3:26pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/10 "2023-01-05T15:26:22Z")
Maybe what i meant were element number. See the Last couple of Posts Here…[Why is Moment load in conjunction to Pressure and Gravity not solving for more than 10mins on 6 cores - #19 by datsnl](https://prepomax.discourse.group/t/why-is-moment-load-in-conjunction-to-pressure-and-gravity-not-solving-for-more-than-10mins-on-6-cores/92/19) ---
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 5, 2023, 7:09pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/11 "2023-01-05T19:09:09Z")
Finally I have solved large problem by using pardiso with additional settings but results are very strange total “0” stresses displacements and so on best regards ![results](https://global.discourse-cdn.com/free1/uploads/prepomax/original/1X/752ca442a7efbf034dbd0ad44840a896ecc7e2b7.jpeg) ---
**Author:** ![SergioP1975](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/sergiop1975/32/37_2.png) [@SergioP1975](https://prepomax.discourse.group/u/SergioP1975)\ **Post date:** [January 5, 2023, 8:36pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/12 "2023-01-05T20:36:42Z")
When the solver gets out of memory, it fails to writte the results. Definitely you must use shell element in such kind of structures. ---
**Author:** ![ANYS](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/anys/32/7737_2.png) [@ANYS](https://prepomax.discourse.group/u/ANYS)\ **Post date:** [January 5, 2023, 9:33pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/13 "2023-01-05T21:33:29Z")
It seems there is some symmetry ¿isn’t it? Maybe you can take some advantage of it. ---
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 5, 2023, 10:19pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/14 "2023-01-05T22:19:13Z")
Loads are not symmetric … acc to eurocode ---
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 5, 2023, 10:23pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/15 "2023-01-05T22:23:37Z")
I have question for 64 gb ram is it possible to solve linear static model with 4,5 millions of nodes I mean ooc version for pardiso or less convenient Iterative cholesky ? best regards ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [January 6, 2023, 9:06pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/16 "2023-01-06T21:06:56Z")
I would recommend simplifying the model or using a coarser mesh and then using sub-modelling to analyze the critical parts of the model [PrePoMax & CalculiX - Submodel - YouTube](https://www.youtube.com/watch?v=-GcpCNbBcA8) ---
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 7, 2023, 7:46pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/17 "2023-01-07T19:46:30Z")
I have solved this large model by using iterative solver (Cholesky) but I have noticed some problems see attached photos Have You got any idea how to solve it best regards ![problem01](https://global.discourse-cdn.com/free1/uploads/prepomax/original/1X/44877be563cd1737d10738818e8e6a1a7aad3d95.jpeg) ![problem](https://global.discourse-cdn.com/free1/uploads/prepomax/original/1X/41c3880beb2f43464c6321071b8b3f92b74deff4.jpeg) ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [January 7, 2023, 8:02pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/18 "2023-01-07T20:02:28Z")
Enable adjustment and increase tolerance for this tie constraint. ---
**Author:** ![Matej](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Matej](https://prepomax.discourse.group/u/Matej)\ **Post date:** [January 7, 2023, 9:28pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/19 "2023-01-07T21:28:17Z")
I am interested in the time it took to solve such a large model. ---
**Author:** ![Michal](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@Michal](https://prepomax.discourse.group/u/Michal)\ **Post date:** [January 7, 2023, 9:44pm UTC](https://prepomax.discourse.group/t/solver-for-large-models/660/20 "2023-01-07T21:44:51Z")
Ca 30 hours model was reduced to ca 2,5 million nodes [Next page](https://prepomax.discourse.group/t/solver-for-large-models/660.md?page=2)