No way. Even with equal-efficient code, there is an additional point that is often ignored: Data structures are way more simple in C, with less overhead, and with higher cache-hit ratio, because more data fits in CPU data cache.<p>As example, gcj is as fast as g++ for code generation (both generating machine code, without virtual machine involved), however, in benchmarking appears to be slower, just because the data structures. If you tweak the Java code for use simpler data structures, e.g. integer or byte arrays, data overhead gets reduced, so memory cache hit increases, thus keeping similar performance to C/C++.<p>Other cases, like Java bytecode running on a VM, even with great JIT like HotSpot, suffers also <i>a lot</i> because of data structures, so even when generated code is quite decent (runtime profiling, etc.), penalty is there, so code will suffer great penalty unless running with huge L3 cache (e.g. 32-48MB), being noticeable anyway no matter how much cache you add when having to do many memory indirections more.<p>And of course, when comparing, you have to compare equivalent things, e.g. Java <-> C/C++ ports, and not completely different software with different implementation (e.g. optimized built-in string handling vs non-optimized C string handling -e.g. ASCIIz string handling is slow, because of stupid C string function implementation, not because the C language itself, being the reason of C strings not being used for high performance code, even when writting in C-).