GCC or rather G++ has the reputation of notoriously creating slow and poorly optimized compiled code, while modern java VMs can profile and optimize the same code for different tasks in run-time.

Here is an article from somebody who did the right tests to prove that Java is faster than C++
http://www.kano.net/javabench/index
http://www.kano.net/javabench/data

This is another interesting article on the same topic (and a little less biased) although a little older:
http://www.idiom.com/~zilla/Computer...benchmark.html