MPS 2018.1 Help

Tuning MPS

Besides the standard options available in the Settings/Preferences dialog, MPS enables you to perform low-level configuration. This requires a certain level of understanding to avoid unexpected problems. It is strongly recommended that you contact JetBrains Support for instructions regarding the options and values that might help you with whatever issue you are trying to solve.

Configuring 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 following file:

<IDE_HOME>\bin\mps64.exe.vmoptions (for the default 64-bit JVM)
<IDE_HOME>\bin\mps.exe.vmoptions (for optional 32-bit JVM)
MPS.app/Contents/bin/mps.vmoptions
<IDE_HOME>/bin/mps64.vmoptions (for the default 64-bit JVM)
<IDE_HOME>/bin/mps.vmoptions (for optional 32-bit JVM)

To configure JVM options:

  • On the Help menu, click Edit Custom VM Options.

MPS creates a copy of the file with JVM options in the configuration directory and opens it in a new editor tab. Any values that you change in this file will override the values from the original default file.

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 JVM options. The values in this file will override corresponding values from both the original default file and the copy located in the MPS configuration directory.

Common options

Default JVM options should be optimal in most cases, but you can fix many problems with performance by configuring some of them. The following are the most commonly modified JVM options:

OptionDescription
-Xmx Limits the maximum memory heap size that the JVM can allocate for running MPS. 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 -Xmx2048m.
-Xms Specifies the initial memory allocated by the JVM for running MPS. Default value depends on the platform. If you feel that MPS starts up slowly, you may want to increase this value. It should usually be about half of the maximum allowed memory (-Xmx), for example, -Xms1024m.
-XX:NewRatio 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 several 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 -XX:NewRatio=1, which will make the young generation as large as the old generation, allowing objects to remain in the young generation for longer.

For more information about available JVM options, see the java reference for Windows or macOS/Linux.

Configuring 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 following file:

<IDE_HOME>\bin\idea.properties
MPS.app/Contents/bin/idea.properties
<IDE_HOME>/bin/idea.properties

To configure platform properties:

  • On the Help menu, click Edit Custom Properties.

MPS creates an empty idea.properties file in the configuration directory and opens it in a new editor tab. Any properties that you add to this file will override the corresponding properties in the original default file.

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 corresponding properties in both the original default file and the one located in the MPS configuration directory.

Common properties

The following properties are commonly changed by users solving specific issues:

  • Location of the default IDE directories may need to be moved, for example, if the user profile drive runs out of space or it is on a slow disk, if the home directory is encrypted (slowing down the IDE) or located on a network drive, if you want to create a portable installation or exclude caches from home directory backups, and so on.

    You can use macros with any property name to insert its value, for example, use ${user.home} (standard Java system property) to specify paths relative to the user's home directory.

    PropertyPath to ...
    idea.config.pathConfiguration directory
    idea.system.pathSystem directory
    idea.plugins.pathPlugins directory
    idea.log.pathLogs directory
  • Limits that can affect performance:

    PropertyDescription
    idea.max.content.load.filesize Maximum size of files (in kilobytes) that MPS is able to open. Working with large files can affect editor performance and increase memory consumption. Default value is 20000.
    idea.max.intellisense.filesize Maximum size of files (in kilobytes) for which MPS provides code assistance. Code assistance for large files can affect editor performance and increase memory consumption. Default value is 2500.
    idea.cycle.buffer Maximum size of the console cyclic buffer (in kilobytes). If the console output size exceeds this value, oldest lines are deleted. To disable the cyclic buffer, set idea.cycle.buffer.size=disabled.
    idea.max.vcs.loaded.size.kb Maximum size (in kilobytes) that MPS loads for showing past file contents when comparing changes. Default value is 20480.

MPS provides a number of other properties that define interaction with the environment (window managers, launchers, file system, and so on). Most of them are like hidden settings (in the sense that they are not evidently exposed), which may need to be enabled or disabled in certain cases. It is strongly recommended to change these properties only after contacting JetBrains Support for assistance.

Selecting the Java runtime for MPS

MPS includes JetBrains Runtime (based on OpenJDK 8), which is used by default.

To switch the Java runtime used to run MPS:

  1. On the Help menu, click Find Action, or press N/A.
  2. Find and select the Switch IDE boot JDK action.
  3. Select the desired JDK and click OK.

The path to the selected runtime is stored in the mps.jdk file in the MPS configuration directory. To revert to the default JetBrains Runtime, you can delete this file, or modify the path to point to another Java runtime.

You can also override the runtime used for MPS by adding the MPS_JDK environment variable with the path to the desired JDK home directory.

Default IDE directories

By default, MPS stores user-specific files (configuration, caches, plugins, logs, and so on) in the user's home directory. However, you can change the location for storing those files, if necessary.

Configuration directory

The MPS configuration directory contains XML files with personal settings, such as, keymaps, color schemes, and so on. It is also the default location for user-defined VM options and platform properties files.

Syntax
%HOMEPATH%\.<product><version>\config
Example
C:\Users\JohnS\.IntelliJIdea2017.3\config
Syntax
~/Library/Preferences/<product><version>
Example
~/Library/Preferences/IntelliJIdea2017.3
Syntax
~/.<product><version>/config
Example
~/.IntelliJIdea2017.3/config

You can change the location of the MPS configuration directory using the idea.config.path property.

You can share your personal IDE settings by copying the files from the configuration directory to corresponding folders on another MPS installation. Make sure that MPS is not running to avoid erasing the copied files when you shut down the IDE. The following table lists subfolders in the MPS configuration directory and corresponding settings that are contained in them:

DirectoryUser settings
codestylesCode style schemes
filetypesUser-defined file types
keymapsCustomized keyboard shortcuts
optionsVarious options, for example, feature usage statistics and macros
shelfShelved changes

System directory

The MPS system directory contains caches and local history files.

Syntax
%HOMEPATH%\.<product><version>\system
Example
C:\Users\JohnS\.IntelliJIdea2017.3\system
Syntax
~/Library/Caches/<product><version>
Example
~/Library/Caches/IntelliJIdea2017.3
Syntax
~/.<product><version>/system
Example
~/.IntelliJIdea2017.3/system

You can change the location of the MPS system directory using the idea.system.path property.

Plugins directory

The MPS plugins directory contains user-installed plugins.

Syntax
%HOMEPATH%\.<product><version>\config\plugins
Example
C:\Users\JohnS\.IntelliJIdea2017.3\config\plugins
Syntax
~/Library/Application Support/<product><version>
Example
~/Library/Application Support/IntelliJIdea2017.3
Syntax
~/.<product><version>/config/plugins
Example
~/.IntelliJIdea2017.3/config/plugins

You can change the location of the MPS plugins directory using the idea.plugins.path property.

Logs directory

The MPS logs directory contains product logs and thread dumps.

Syntax
%HOMEPATH%\.<product><version>\system\log
Example
C:\Users\JohnS\.IntelliJIdea2017.3\system\log
Syntax
~/Library/Logs/<product><version>
Example
~/Library/Logs/IntelliJIdea2017.3
Syntax
~/.<product><version>/system/log
Example
~/.IntelliJIdea2017.3/system/log

You can change the location of the MPS logs directory using the idea.log.path property.

Last modified: 24 January 2018