Trouble is, you don't tend to write a big program in two languages the exact same way. The rewrite nearly always wins because of algorithm improvements and clea

Trouble is, you don't tend to write a big program in two languages the exact same way. The rewrite nearly always wins because of algorithm improvements and cleaning cruft. So it's hard to benchmark. If two small programs are about the same speed in C vs JITlang, then the theory says the JITted one should take over as the program gets bigger.