Reducing memory usage

Bisq is known to be a resource-hungry application, so some users may want to reduce memory usage.

Command-line fix

Reduce Bisq's memory usage by setting a ceiling of 4GB:

JAVA_TOOL_OPTIONS="-XX:MaxRAM=4g" /opt/bisq/bin/Bisq

/opt/bisq/bin/Bisq is the default application directory on Linux. If you run another operating system, you'll need to replace that path with the one for your OS.

You can adjust the scaling factor as you wish, of course, and add any runtime options for Bisq as well.

GUI fix

To be able to launch the fix by double clicking an icon, rather than running a command in CLI, you can edit the launcher file to run, instead of the Bisq app directly, a shell script which injects said fix.

1. Create a text file (for example /opt/bisq/Bisq-runner.sh) containing the following code:

#!/bin/bash
JAVA_TOOL_OPTIONS="-XX:MaxRAM=4g" /opt/bisq/bin/Bisq

2. Make it executable:

chmod +x /opt/bisq/Bisq-runner.sh

3. Edit the launcher file (/opt/bisq/Bisq.desktop and/or /usr/share/applications/Bisq.desktop) by opening it in a text editor and modifying the Exec line like follows:

Exec=/opt/bisq/Bisq-runner.sh

Background

One of the settings Java virtual machines (JVMs) use to calibrate how much physical memory to reserve at startup is MaxRAM, and there is a good chance your JVM's default MaxRAM configuration is too large.

To check the default MaxRAM setting, run this java command:

java -XX:+UnlockDiagnosticVMOptions -XX:+PrintFlagsFinal -version | grep MaxRAM

Look for the MaxRAM value (bytes) in the output. An example:

367: uint64_t MaxRAM = 137438953472 

This means the OpenJDK 11 JVM's MaxRAM setting is 128GB, much more RAM than the average desktop machine has.

Experiments have shown running Bisq with a 4GB MaxRAM setting reduces memory consumption by more than 50% (when starting a clean Bisq installation with an empty data directory). Setting MaxRAM to 2GB reduces resident memory usage even more, but setting it any lower (1536m) will result in an OutOfMemoryError and crash the app.

As of version 1.3.2, Bisq starts with a MaxRAM setting of 4GB. If you're still having issues, try setting the parameter yourself as described above.