I'm not sure what is the procedure to improve the FAQ...
It is quite annoying to see repeated questions posting some code and measurements -- then eventually revealing that unoptimized compile was used.
Most comments will certainly go around that point, and answers turn out irrelevant once optimizaitions are turned on, as they should have been in the first place.
Those threads are hardly ever constructive, with the only thing to (re)learn is that raw/debug compile is no good for performance measurements and tweaking.
I suggest to put that category in the FAQ as bad/unwanted question in that way.
EDIT: I'm also interested in structured alternatives, community wiki or something?