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"Out of memory when xmesh processing" and issue with allocating only a fraction of the available RAM.

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Hi everyone,

I have a COMSOL Multiphysics 5.5 model where a beam of ions is travelling through an assembly of electrodes. I inherited the model from another person, and I am trying to run it.

My problem is that, although my PC has 8 GB of RAM, when the model runs, the virtual memory it allocates never exceeds ~5.5 GB, and it always fails, giving an error message "Out of memory when xmesh processing." I do not actually understand what this message means (new to COMSOL) and I need help figuring out a way to make the model allocate a larger fraction of RAM.

To make it run, I tried to use the direct solver (MUMPS) with out-of-core ON, but now instead of failing, the model completely crushes the computer. The original model had a lot more components in it, but I removed a lot of them and only kept the absolutely necessary ones. I made the mesh extremely coarse except at boundaries where a coarse mesh would throw an error, but the problem still persists.

Is there an established practice to manage COMSOL memory? Has anyone experienced similar issues before?


1 Reply Last Post 12.11.2020, 12:38 GMT-5

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Posted: 4 years ago 12.11.2020, 12:38 GMT-5

As an update, this is the log that comes out when it fails:

<---- Compile Equations: Stationary in Study 2/Solution 1 (sol1) --------------- Started at Nov 12, 2020 6:35:44 PM. Geometry shape order: Quadratic Geometry shape order: Quadratic Running on Intel64 Family 6 Model 42 Stepping 7, GenuineIntel. Using 1 socket with 4 cores in total on pccris30. Available memory: 8.07 GB. Number of vertex elements: 980 Number of edge elements: 3577 Number of boundary elements: 13858 Number of elements: 17738 Free meshing time: 6.26s Minimum element quality: 0.004852 Warning: Low minimum element quality Time: 59 s. Physical memory: 2.03 GB Virtual memory: 4.49 GB Ended at Nov 12, 2020 6:36:44 PM. ----- Compile Equations: Stationary in Study 2/Solution 1 (sol1) -------------->

As an update, this is the log that comes out when it fails:

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