Well, we all know that the most crucial feature of the JVM runtime is the -version output. So how does the OpenJDK (in the form of SapMachine) compare with GraalVM? It’s significantly faster. Using hyperfine, we can see that GraalVM 25 CE takes almost twice as long to emit the version number as a regular SapMachine 25 on my MacBook Pro M5:
The slowness of java -version was actually one of the performance issues of the tool I showcased in How to Build an Executable from a JAR using ExecJAR, as it originally used java -version a lot to check the Java version constraint.
Is this relevant? Not really. However, so are most microbenchmarks and benchmarks in general that are taken out of context. You should not generalize small benchmarks, and modern systems are complex.
Join me next week for a blog post on something different and learn how to check the version of a Java installation even faster in under one millisecond:
P.S.: I just ran some more benchmarks: OpenJDK 25 is 18% faster than OpenJDK 17 and 21 and a whopping 84% faster than OpenJDK 11. Upgrade now!
P.P.S.: As many people (Thomas Wuerthinger, Fabio Niebhaus, Volker Simonis, and multiple of my SapMachine colleagues) pointed out, the differences between OpenJDK and GraalVM are due to the GraalVM initializing the JVM Compiler Interface (JVMCI). The difference between the two becomes negligible when running OpenJDK with enabled JVMCI (initialize the JIT at the beginning):
Johannes Bechberger is a JVM developer working on profilers and their underlying technology in the SapMachine team at SAP. This includes improvements to async-profiler and its ecosystem, a website to view the different JFR event types, and improvements to the FirefoxProfiler, making it usable in the Java world. His work today comprises many open-source contributions and his blog, where he regularly writes on in-depth profiling and debugging topics. He also works on hello-ebpf, the first eBPF library for Java. His most recent contribution is the new CPU Time Profiler in JDK 25.
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