tweak FreeBSD 8 for optimal java/weka performance

[Dino Vliet]

Dear freebsd people,
 
in a few days I will install freebsd 8.0 amd64 on my 8GB RAM dual core machine and use the system as a application server. I will install the /usr/ports/textproc/weka toolkit, a program written in java. I will use the diablo jdk port in /usr/ports/java.
 
Due to the nature of the research I will be doing I will need to max out my machine for optimal java performance. For example, I will use the -Xmx7g flag frequently to set the maximun java heap size to 7GB.
 
Are there any other tweaks I should think of to get as much RAM for my java programs?
Like building custom and small kernel, in order to minimize te size of the kernel?
 
Let me know,
thanks in advanced,
Dino