Performance of Java 1.6 vs C++?

Question

With Java 1.6 out can we say that performance of Java 1.6 is almost equivalent to C++ code or still there is lot to improve on performance front in Java compared to C++ ?

Thanks.

Answer 1

Debian likes to conduct benchmarks on this sort of thing. In their case, it appears that Java is about half as fast and consumes 2-18 times as much memory as C++.

Answer 2

A well-written Java program is never going to be as fast as a well-written C or C++ program. The virtual machine is an irreducible overhead. However, most code is not well written.

Java is a simpler language than C++, and offers a more forgiving environment for inexperienced programmers - so if your programmers are inexperienced (and cheap), then Java will probably perform 'better' than C++.

shared_ptrs offer a similarly forgiving environment in C++, so they are very tempting for inexperienced programmers, or those migrating from Java, But their performance overhead is as bad or worse than Java's garbage collection. I've seen large C++ programs where every variable is a shared_ptr, and they perform terribly.

My opinion

Personally, I think that large projects need to choose an 'easy' programming language for the bulk of their code, and a 'fast' one for sections that need optimising. Java may be a good choice for the 'easy' language, especially since there is currently a plentiful supply of Java programmers - in the future, I think even easier languages such as Python will begin to take over.

C++ is a reasonable choice for a 'fast' language if you already know it, but I think it's over-complexity will eventually see it fall by the wayside, while C will continue to fulfill this role.