This is an old discussion, but I actually have this thread bookmarked so I can show young programmers the dangers of assuming that if you write in C++ it will be faster then everything else out there.
Actually C was the fastest, by a fairly wide margin, however hat doesn't matter much since you can make the C++ faster and you can make C go just as slow as the input buffered C. There are still lots of people who think that speed is solely a function of programing language with very little impact from program design. Like I said I like to bring this out when showing newer developers that no matter what language you pick you need to be aware of what is going on in the background and most importantly you should test you code before trying to assume what parts are fast and what parts are slow.
Maybe the sensible takeaway is that if you can do a prototype in a simpler language first to establish a baseline, you should.
I think most people expect that they can, due to their own ignorance, make a slow program even in C++.
You're right, it is an odd conclusion, but lots of folks think that way. That's why Negitivefrags needs to dissuade inexperienced folks of that notion.
I (re)learned the same lesson last year when I started looking at OpenCL. I saw all these awesome benchmarks about it was 40-50 times faster than C. I then did a bunch of simple tutorials and tests and got great performance. Then I rewrote a piece of performance critical C code I had and after a couple of days of hard work I had something that ran 5 times slower than my original C code.
