Is there a way to allow an Intel GMA 4500 integrated graphics card to use more of the system RAM for graphics?

I play RCT3, an intensive 3D game, and it's kind of choppy with this card. I know that the card has no memory of its own, and that it "steals" memory from the system. How do I set the graphics card to use more system memory than the minimum amount it needs to run the game?