The latest update to the SDK is now available on the Downloads page.

Fix pack 16 ( includes extended platform support for the idle tuning feature plus a new option that can improve the performance of applications that run in containers by automatically allocating a larger proportion of the available memory to the Java heap.

Idle tuning feature

This feature allows your application to run with a minimal memory footprint by identifying objects that are no longer referenced and releasing unused memory back to the operating system. In earlier refreshes, this feature was available only on Linux x86 architectures with the gencon garbage collection policy. From fix pack 16, this feature is now available on Linux for IBM POWER® and IBM Z® architectures. You can read more about idle tuning in this recent blog post.

Maximizing your Java heap size for applications that run in a container

When using container technology, applications are typically run on their own and do not need to compete for memory. In this release, changes are introduced to detect when the Eclipse OpenJ9 virtual machine (VM) is running inside a container. If your application is running in a container and you want the VM to allocate a larger fraction of memory to the Java heap, set the -XX:+UseContainerSupport option on the command line. For containers that have more than 2 GB of memory, the default maximum Java heap size is set to 75% of the available memory. With more heap available to your application, less time should be spent in garbage collection and you should see an improvement in performance throughput.

This refresh also contains the latest IBM fixes to the code base. You can find out more about these fixes on our fixes page.

2 comments on"IBM SDK, Java™ Technology Edition, Version 8, Service Refresh 5, Fix Pack 16"

  1. Hello,
    we are a software developer and an IBM partnerworld member.
    We would like to know if we are able to include IBM JDK for AIX and Host a part of our software delivery. If we are able to deliver it, are we able to unpack it or in what status should it be delivered?
    We have an NDA with IBM.
    I am not sure if you are the correct person, if not could you kindly point me in the right direction.

    Best regards,

    • Sue Chaplain July 18, 2018

      Hi Niki,

      Thanks for your interest! Please can you send an email to and provide as much information as possible. We’ll then be able to put you in touch with the most appropriate person to help you.

      Best Regards,

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