Tested 5 boxing on 1 PC - Question

Sup guys. I finally got a 2nd monitor last night and I bought my 4th copy of wow.

Quad boxing on my system works pretty well. A little bit of lag in major cities upon entering (but it goes away completely after 10-30 sec).

I made a 5th account (free trial) to test 5 boxing. WOW. huge difference...impossible in major cities. (starting zones were fine though..no lag at all)

The weird thing is my FPS (on my main) was constantly jumping between 30-55.

So as far as the lag issues I was having....I'm guessing my video card is not the problem (since my fps didnt drop below 30). I'm *guessing its either the processor or the memory that is the problem.

I'm wondering if simply adding another 2 GB of memory would allow me to run 5 copies. Or if getting a better processor would.

I'll be building a 2nd computer within the next couple of months...but If getting more memory or upgrading processor would do the trick...I'd rather go that route for now.

What do you guys think the major cause of lag is?

System:

Radeon X1950PRO 256MB
Intel Core 2 Duo - 2.13 GHZ
2 GB DDR2- G.SKILL 6400

I have a similar setup to yours with a slightly faster processor and when I five box I'm using around 3G of RAM according to Vista. So try the 4G upgrade first.