The Java Virtual Machine (JVM) running IntelliJ IDEA allocates some predefined amount of memory. The default value depends on the platform. If you are experiencing slowdowns, you may want to increase the memory heap.
Heap size is not the total memory limit, the value of -XX:PermSize is also added to this number, plus stack size for every thread, plus memory mapped files, plus internal JVM memory for the JIT compiler and other needs. All these factors make it easy to get close or exceed the 2GB value. So the heap size is total amount of memory that Intellij can use to operate.-XmxmemoryVal - Specifies the maximum memory allocation of the heap for the VM. This is the maximum amount of memory Intellij can use. Phpstorm (50) pycharm (36).
Phpstorm Heap Size Error
If you want to configure the heap size for the build process that compiles your code, open Settings/PreferencesCtrl+Alt+S, select Build, Execution, Deployment | Compiler, and specify the necessary amount of memory in the Build process heap size field.
From the main menu, select Help | Change Memory Settings.
Set the necessary amount of memory that you want to allocate and click Save and Restart.
This action changes the value of the -Xmx option used by the JVM and restarts IntelliJ IDEA with the new setting.
The Change Memory Settings action is available starting from IntelliJ IDEA version 2019.2. For previous versions or if the IDE crashes, you can change the value of the -Xmx option manually as described in JVM options.
Phpstorm Heap Size Increase
IntelliJ IDEA also warns you if the amount of free heap memory after a garbage collection is less than 5% of the maximum heap size:
Click Configure to increase the amount of memory allocated by the JVM. If you are not sure what would be a good value, use the one suggested by IntelliJ IDEA.
Phpstorm Heap Size Limit
Click Save and Restart and wait for IntelliJ IDEA to restart with the new memory heap setting.
Enable the memory indicator
IntelliJ IDEA can show you the amount of used memory in the status bar. Use it to judge how much memory to allocate.
Right-click the status bar and select Memory Indicator.
Toolbox App
If you are using the Toolbox App, you can change the maximum allocated heap size for a specific IDE instance without starting it.
Open the Toolbox App, click next to the relevant IDE instance, and select Settings.
In the instance settings dialog, expand Configuration and specify the heap size in the Maximum heap size field.
If the IDE instance is currently running, the new settings will take effect only after you restart it.
If you are using a standalone instance not managed by the Toolbox App, and you can't start it, it is possible to manually change the -Xmx option that controls the amount of allocated memory. Create a copy of the default JVM options file and change the value of the -Xmx option in it.