when you have eliminated the impossible, whatever remains, however improbable, must be the truth.
You've got some data in one hand, and an assumption (C++ is always faster than Java) in the other. Why ask for people to justify your assumption when the data tells you otherwise?
If you wish to obtain assembly from the JVM in order to compare what's being run then the commandline option is '-XX:+PrintOptoAssembly', but you'll need to download a debug jvm in order to do so. Looking at the assembly would at least tell you why one is faster than the other.
