i think the problem is that there are just too many things to consider... basically though:
php -> typically compiled into apache, makes for faster processing, and not a lot of overhead
cgi -> opens a new process for each call which is expensive, however, mod_perl / mod_python gives it basically the same "edge" as php for those particular langauges
asp -> (chilisoft) runs it's own server, so you have that additional overhead
coldfusion -> ditto.. doesn't it? (don't have much experience with it) i think MX runs on top of a java server, not sure if that means additional overhead although i'd imagine it may...
jsp/java -> runs it's own server, as well, can be problematic in a shared environment as you need to restart the server (which typically takes longer than say restarting apache) whenever you add a new user, new servlet, etc... unless you use reloadable servlets which adds more processing.
the above is really not a very technical look (i mean i coudln't tell you if resin / tomcat / jrun, etc.. run better...), just kinda how the environment is setup, which should provide some clues as to a "if everything were equal". people usually point to tomcat and what not being more scalable though when you start really putting stress on an application, so again, i suppose it really depends on what you're doing with it... i'd suggest that since asp / jsp / coldfusion run separate servers, you're taking that additional hit on resources, but really it's all just tradeoffs as to what you get out of it vs what your hardware can take...
for your everyday "normal" stuff though, i'd think php generally would be "fastest"
I think that is very debatable. But apologize if it is in a wrong forum.
i am a:
Yes, you are correct with Cold Fusion. It runs its own server and has more overhead. With MX I think you are correct that is run on top of Java, though not all that sure. All I know is I tested MX for a while and the speed of it was extremely worse then Cold Fusion 5. Plus, being very new, it had significant problems like on the rare occasion it would not load a page for 8 or so seconds while the processor would remain 99% idle.
From my experiences I would concur and say that PHP seems to be the best in terms of system resources. However, I also find it not as easy to develop as CF. Dont get me wrong, I wrote both PHP and PERL scripts for quite a while and can get everything done that is needed, its just that Cold Fusion gears more towards web development. Never had experience with ASP or JSP though.