Asus K8N4-E -- RAM question(2GB @ DDR400 vs 3GB @ DDR333)

Question for those more knowledgeable than myself:

I recently upgraded to Age of Conan from World of Warcraft, and I'm noticing that my machine is doing a lot of swapping, so it's time to add some more RAM. Currently running 1.5g (3x512 no-name un-matched leftover junk ram). I was planning on dropping 3x1G sticks in and calling it good, but looking over the "Recommended DDR memory configurations" section of my mobo manual, I see that the # and type of modules I use will affect the memory bus clock rate...

The relevant info from the MB manual:

# of DIMMS       DIMM1             DIMM2          DIMM3             Max Speed

       2         Double            Empty          Double            DDR 400

       3         Single            Single         Single            DDR 333

Configuration 1 limits me to 2 DIMMs, or 2GB total memory.
Configuration 2 allows me to have 3GB of memory, but at a lower clock rate.

CPUId reports that I'm currently running @ DDR 200 speed, so either of these would be both a speed & a size improvement for me.

Which of these configurations am I more likely to see better performance from?

Thanks for any replies.