“Benchmarks are only as good as the programs they measure,” Cox said. “We used gopprof to study an inefficient Go program and then to improve its performance by an order of magnitude and to reduce its memory usage by a factor of six. A subsequent comparison with an equivalently optimized C++ program shows that Go can be competitive with C++ when programmers are careful about how much garbage is generated by inner loops.”

via Google Go strikes back with C++ bake-off • The Register.