I've seen several queries from different quarters about configuring the MME for optimal performance.
The answers to at least some of these questions are in the MME documentation. Many are in the MME Configuration Guide; 
however, more information about configuring io-media, for instance, is in the io-media documentation in the MME 
Utilities Guide.
In short, have a look have a look at both these books.
And please do keep me posted of gaps, so I can keep improving the information.