I have a friend at Intel who works on their realtime raytracing efforts and he swears by C/C++. Indeed, his arguments mirrors yours and go even farther. There's all sorts of magic you can play when you've got access to the actual bits and bytes. For starters, they do things like stash data in the low-precision bits of floats and the lower three bits of pointers. I wholeheartedly concur with his opinion that in raw performance terms, C/C++ is the fastest.

The problem with his argument and yours is that C is NOT faster for The Rest of Us because it it amounts to premature optimization just by virtue of using it. And because it takes so much effort to get C code to just work, the WHOLE program ends up being slower than the corresponding code in Haskell, OCaml, or perhaps even CLisp. Having worked my last job in a company where the programmers preferred C to C++ and C++ to Python, it startles me how utterly slow our system was. And ditto for the previous job.

At my first place, we had a streaming video server that had blindingly fast compression routines, but it was all held up by a UI loop that harked from the prototype days. Thus the argument that C/C++ is/are the best languages for fast code is moot. It is only the fastest if you've all the time in the world to write it.