I know the mantra of the GB PC board has always been "four gigs of RAM is plenty!" well, let me tell you, that's bullshit! I've had my rig that I built a little over a year with 4 gigs in it, and after getting tired of noticeable lag in application switching, and a general lack in performance, I broke down and bought 16 gig, the max my mobo can support. WHAT A FREAKING DIFFERENCE!! All in all it cost me $110, and now my computer is blazing fast again.
If you're building a rig kick anyone in the nuts who tells you "4 gigs is plenty" and throw the max in that puppy.