Advanced configuration
Besides the standard options available , MPS enables you to perform low-level configuration of the underlying platform and the Java runtime.
JVM options
MPS runs on the Java Virtual Machine (JVM), which has various options that control its performance. The default options used to run MPS are specified in the IDE installation directory:
<IDE_HOME>\bin\mps64.exe.vmoptions
MPS.app/Contents/bin/mps.vmoptions
<IDE_HOME>/bin/mps64.vmoptions
Configure JVM options
Do one of the following to create a copy of the default file with JVM options in the configuration directory that will override the original file:
From the main menu, select .
If you do not have any project open, on the Welcome screen, click Configure and then Edit Custom VM Options.
If you cannot start MPS, manually copy the default file with JVM options to the MPS configuration directory.
If you do not have write access to the MPS configuration directory, you can add the MPS_VM_OPTIONS environment variable to specify the location of the file with your preferred JVM options. This file will override both the original default file and the copy located in the MPS configuration directory.
Locate the JVM options file
If you are not sure where MPS is getting its JVM options, check the following:
The location specified by the
MPS_VM_OPTIONSenvironment variable. If the specified file exists, it will override all other JVM options files.If the Toolbox App manages your current MPS instance, open the Toolbox App, click
next to the relevant IDE instance, and select Settings. Under Configuration, find Java Virtual Machine options and click Edit.If you are running a standalone MPS instance, check the configuration directory.
If there are no JVM options files defined in the previous locations, MPS will use the default JVM options file. Do not modify it. Use it only to check what are the default options that MPS uses.
Common options
The default values of the JVM options should be optimal in most cases. The following are the most commonly modified ones:
Option | Description |
|---|---|
| Limits the maximum memory heap size that the JVM can allocate for running MPS. The default value depends on the platform. If you are experiencing slowdowns, you may want to increase this value, for example, to set the value to 2048 megabytes, change this option to |
| Specifies the initial memory allocated by the JVM for running MPS. The default value depends on the platform. It is usually set to about half of the maximum allowed memory (-Xmx), for example, |
| Specifies the ratio between the size of the young and old generation of the heap. In most cases, a ratio between 2 and 4 is recommended. This will set the size of the young generation to be 1/2 to 1/4 of the old generation correspondingly, which is good when you are often working on one project and only a few files at a time. However, if you are constantly opening new files and switching between several projects, you may need to increase the young generation. In this case, try setting |
For more information about the available JVM options, see the java command reference.
Platform properties
MPS enables you to customize various platform-specific properties, such as the path to user-installed plugins and the maximum supported file size. The default properties used to run MPS are specified in the IDE installation directory:
<IDE_HOME>\bin\idea.properties
MPS.app/Contents/bin/idea.properties
<IDE_HOME>/bin/idea.properties
Configure platform properties:
Do one of the following to create an empty idea.properties file in the configuration directory that will override the values from the original file:
From the main menu, select .
If you do not have any project open, on the Welcome screen, click Configure and then select Edit Custom Properties.
If you cannot start MPS, manually create an empty idea.properties file in the MPS configuration directory.
If you do not have write access to the MPS configuration directory, you can add the MPS_PROPERTIES environment variable to specify the location of the idea.properties file. The properties in this file will override the corresponding properties in both the original default file and the one located in the MPS configuration directory.
Common properties
Users often change the location of the default IDE directories. For more information, see Change the location of IDE directories.
Limits that can affect performance:
Property | Description |
|---|---|
| Maximum size of files (in kilobytes) that MPS is able to open. Working with large files can affect editor performance and increase memory consumption. The default value is |
| Maximum size of files (in kilobytes) for which MPS provides coding assistance. Coding assistance for large files can affect editor performance and increase memory consumption. The default value is |
| Maximum size of the console cyclic buffer (in kilobytes). If the console output size exceeds this value, the oldest lines are deleted. To disable the cyclic buffer, set |
| Maximum size (in kilobytes) that MPS loads for showing past file contents when comparing changes. The default value is |
MPS provides a number of other properties that define interaction with the environment (window managers, launchers, the file system, and so on). Most of them act like hidden settings (in the sense that they are not evidently exposed), which you may need to enable or disable in certain cases. Change these properties only if advised by JetBrains Support.