Your analogy to native vs. byte code is apt, but the question is not whether we can JIT-compile byte code to run as fast as native code (we can). The question i

Your analogy to native vs. byte code is apt, but the question is not whether we can JIT-compile byte code to run as fast as native code (we can). The question is, what instruction set allows us to write the best compilers. I would argue that the answer is RISC. Every time Intel adds yet another instruction for doing the same thing, it makes every compiler's job harder. Intel's C compiler is faster than most others because they know their overly convoluted instruction set best. Simpler instruction set means more resources to focus on the few instructions that exist both for the chip manufacturer and the compiler vendors. On a somewhat related note, Java byte code uses a very-Reduced ISC, a simple stack machine.