Going to the Tweakers Page could be helpful for you. They list the things needed to keep a "balanced" system according to the way these programs use resources. Paying for a hot video card when your RAM sucks isn't sensible, is it? It all ties in together. In at times weird ways.
So ... the more drives connected to the mobo you've got, the better. Externals through sSATA II or Thunderbolt are good. SSD's are of course, good. Say a 5-disc RAID array all connected to the mobo for project files, assets, & such is really awesome. One internal and one external USB3 ... sucks. That sort of thing.
Neil