LibreOffice Embedded Object Memory Settings

This guide explains how to manage and configure memory allocation settings for embedded objects, graphics, and OLE items in LibreOffice. While modern versions of LibreOffice automate most resource management, power users working with complex documents containing large embedded elements can fine-tune specific cache parameters using the built-in Expert Configuration to prevent rendering delays, crashes, or document sluggishness.

Modern Memory Management in LibreOffice

In older releases (prior to LibreOffice 5.4), users could directly access a dedicated “Memory” tab under application options. In contemporary versions, LibreOffice handles resource allocation dynamically based on system hardware. However, manual control over embedded object thresholds is still possible via the Expert Configuration interface.

Accessing Expert Configuration

To configure the memory parameters for graphics and embedded objects:

1. Open LibreOffice.
2. Navigate to Tools > Options (or LibreOffice > Preferences on macOS).
3. In the left panel, expand LibreOffice and select Advanced.
4. Click the Open Expert Configuration button.

Key Settings for Embedded Objects and Graphics

Within the Expert Configuration search bar, enter org.openoffice.Office.Common/Cache to access the relevant properties controlling memory usage:

• GraphicManager/TotalCacheSize
  Controls the maximum amount of RAM (in bytes) allocated for all cached graphics and embedded visual objects across open documents. Increasing this value prevents LibreOffice from constantly reloading heavy images from disk.

• GraphicManager/ObjectCacheSize
  Specifies the maximum memory limit (in bytes) dedicated to any single embedded object. If an embedded object exceeds this threshold, it is swapped out to temporary disk storage more aggressively.

• GraphicManager/ObjectReleaseTime
  Determines the duration (in seconds) that an embedded object remains stored in the memory cache after it is no longer actively displayed on the screen.

• Writer/OleCache
  Defines the maximum number of embedded OLE (Object Linking and Embedding) objects kept in memory simultaneously within LibreOffice Writer.

Modifying Cache Values

1. Double-click the desired entry in the Expert Configuration list.
2. Enter the new value in bytes (for example, 134217728 for 128 MB or 268435456 for 256 MB).
3. Click OK to save the value.
4. Click OK or Apply on the main Options dialog, then restart LibreOffice to apply the changes.

Java Virtual Machine Memory for Embedded Applets

For embedded components that rely on the Java Virtual Machine (JVM):

1. Go to Tools > Options > LibreOffice > Advanced.
2. Select your installed JRE and click Parameters.
3. Add memory limit flags such as -Xmx512m or -Xmx1024m to allocate more heap space to Java-based embedded operations.
4. Click Assign, then restart LibreOffice.