Re:Um, it's online (Score 1)

All tests from this benchmark has been designed for working with arrays of Java primitive types. On such tests JVM optimizer does very good job. But Java is really terrible language, if you need to optimize data representation.

Java performance vs C++ (preferrably with Boehm GC) looks very bad in working with large complex data structures. Probably even on standard sets C++ will be better than Java. If data representation was tuned for speific application needs, gap between C++ and C++ should increase.