Your fps will always be garbage in intermediate mode, try using a draw list or vbo.
No no no no no.
Immediate mode is slower than the other methods for sure, but it's not that much slower. You don't get such dramatic framerate drops from it, particularly with such a simple scene (as polycounts really ramp up it's expected, but with basic scenes it's performance is roughly equivalent to the others). Remember - Quake used immediate mode and didn't suffer overly much from it.
Please don't recommend VBOs (or display lists) as a "solution" every time you see immediate mode code - the real cause of the problem may very well be elsewhere (as, indeed, it was in this case).
I'm not advising that it's OK to use immediate mode here, by the way; I am recommending that you should properly diagnose the problem before recommending a solution, rather than jump to conclusions.
Graphics card makers only optimize their hardware for vbo's these days so its not unreasonable to assume legacy functions can cause all sorts of performance problems.