JavaOne 2026 Session

Summary

Everyone knows Java programs use a garbage collector and that the JDK offers a choice of several GCs with different characteristics. But all of the JDK’s garbage collectors share important design aspects that set them apart from garbage collectors used in other languages, and that Java developers should know. In this talk, we’ll cover why the JDK’s garbage collectors work the way they do and how the JDK’s memory management impacts program performance. In particular, we’ll explore the interesting and sometimes non-obvious relationship between RAM and CPU, and why we must always consider them together. We’ll also ask whether Java is wasteful by using too much memory or whether it's other languages that are wasteful by using too little.