Optimizing Performance

[bower4311]

I'm running Ubuntu 12.04LTS 64 bit hosting and Windows XP 32bit guest. I want to get as much as I can out of my system. I built it and its a core i5 2500k 3.30GHz with 8gb of RAM. How should I go about optimizing for this setup. I can install a 64 bit version of XP if that would be better. I have 2GB of ram set for the VM, should I up it to 4 to split it? If I did that then I wouldn't really need a 64 bit guest would I? I was able to set everything up and it works fine, I just don't know too much about optimizing this stuff.

Thanks for any help,

Adam