Oh, I see! You are a big boy now!
I don't consider myself a beginner, I have over 3 years of c++, c# and game programming behind me but I have not programmed a game with optimized graphics.
MMORPGs require large budgets (tens of millions of dollars is probably the right order of magnitude) and involve hiring lots of people. The details of how to optimize the graphics are something you can ask one the experienced graphics programmers you will need to hire.
I know some people don't like analogies, but this is a bit like wanting to make a movie like Avatar and asking about some technical aspect, like motion capture. While motion capture was important for this movie, what you should be thinking about if you want to make a movie like Avatar is that you need a movie studio and a lot of money. Or you could make some low-budget indie film instead (clicky), or you could get a job in someone else's project so that you can learn how the business works.