However, there's a trade-off: . Each object reference in the heap grows from 4 bytes (32-bit) to 8 bytes (64-bit). This increases memory consumption by approximately 30–50% for the same application, unless you enable Compressed Oops (Ordinary Object Pointers). Compressed Oops: The Game Changer Since Java 7 (and improved in Java 8+), the JVM can use compressed pointers :
If you're still running production apps on a 32-bit JVM, ask yourself: Is it because you genuinely need less than 2 GB of heap, or because you haven't migrated yet? In most cases, the answer is the latter. Make the leap to 64-bit Java—your future self (and your memory-hungry application) will thank you. Have you migrated a large application to 64-bit Java? Share your experience in the comments below.
Example for a 64 GB heap with low-latency requirements: java 64
java -version Look for 64-Bit in the output:
Introduction When developers see the phrase "Java 64," they usually aren't talking about a specific JDK version. Instead, they refer to running Java applications on a 64-bit architecture using the 64-bit Java Virtual Machine (JVM). While 32-bit Java served us well in the early 2000s, modern applications—especially in big data, cloud microservices, and enterprise backends—demand the vast memory space and performance optimizations that 64-bit Java provides. However, there's a trade-off:
It's likely that within a few years, 32-bit Java will become an exotic legacy footnote. Java 64 isn't a version number—it's a capability. Moving to 64-bit opens the door to massive heaps, better throughput for data-intensive workloads, and modern hardware optimization. But success requires understanding compressed pointers, choosing the right garbage collector, and accounting for larger memory overhead.
java version "17" 2021-09-14 LTS Java(TM) SE Runtime Environment (build 17+35) Java HotSpot(TM) 64-Bit Server VM (build 17+35, mixed mode, sharing) Alternatively, programmatically: Compressed Oops: The Game Changer Since Java 7
java -Xms64G -Xmx64G -XX:+UseZGC -XX:+UseCompressedOops To check if you're running a 64-bit JVM: