Allocating Memory

COMSOL Multiphysics stores the data in Java®. If you are experiencing memory problems during meshing, postprocessing operations, or when exchanging data between the COMSOL server and MATLAB®, this can mean that the Java heap size is set with too low a value.


	Increasing the memory allocated for the Java process necessarily decreases the memory available for the solver.

Either set The COMSOL Multiphysics Server Java Heap Size or Setting Manually the Memory in MATLAB.

The COMSOL Multiphysics Server Java Heap Size

The Java heap size settings for the COMSOL Multiphysics Server process are stored in the comsolmphserver.ini file. You can find this file in the COMSOL55/Multiphysics/bin/<arch> directory. <arch> correspond to the architecture of the machine where the COMSOL Multiphysics Server is running (win64, maci64, or glnxa64).

Edit the file with a text editor, the Java heap settings are defined as in the following lines:

The values are given in Mb, modify these value to satisfy the model requirements.

Setting Manually the Memory in MATLAB

To modify the Java heap size you need to edit the java.opts file available under the COMSOL with MATLAB start-up directory. The java.opts file is stored by default with the following settings:

-Xss4m

-Xmx768m

-XX:MaxPermSize=256m

The values are given in Mb, modify these value to satisfy the model requirements.

To modify the MATLAB Java Heap size the java.opts file has to be stored at the MATLAB start-up directory. This is the case when starting COMSOL with MATLAB.


	If you are manually connecting MATLAB with a COMSOL Multiphysics Server, make sure you have the java.opts at the MATLAB start-up directory.