Java Runtime Performance Vs Native C / C++ Code?

Question

I\'ve become more and more comfortable programming in Java than with C++ or C. I am hoping to get a sense of the performance hit incurred using a JVM interpreter, as oppose

Answer 1

Actually, a VM can do a lot of optimizations at runtime, based on information that's only available at runtime, that a C/C++ compiler cannot do. So, in most circumstances, the JVM will be at least as fast as a native program.

Brian Goetz answers most, if not all of your questions in his talk Towards a universal VM.