The JVM is very inflexible in that respect. If you give it more memory it will keep all of it way beyond the point where it matters for performance. If you give

The JVM is very inflexible in that respect. If you give it more memory it will keep all of it way beyond the point where it matters for performance. If you give it less memory you need to know exactly how much less you can give it before performance craters. In other words, JVM deployments need a lot more tuning than Go and they will generally need a lot more memory as well. But you're right, not setting -Xmx at all will make the JVM look worse than it really is.