I think this might be better solved at the application level. For instance, there are probably specialized web servers for this, or you might consider mod_cache with Apache. If you have a specific goal, such as serving web content faster, then you can get improvements form this sort of thing I think.
But your question is general in nature, the Linux memory subsystem is designed to provide the best general use of RAM. If you want to target certain types of performance, consider looking up everything in /proc/sys/vm .
The fcoretools package is interesting, I'd be interested in any articles about its application... This link talks about the actual system calls used in an application.