Well, no integrated card has dedicated memory, it's a part of the motherboard that uses a dynamic amount of system memory (possible up to 1gb-1.7gb, also depends on how much system memory is available).
The issue isn't the amount of memory the card can use, though, its the speed of the card.
The 3000 HD graphics' core clock frequency is 850mhz, and can be pushed to 1100mhz, whereas the Intel 4 Series Express is at a flat 400mhz.
The 3000 HD series can just barely keep up with the game at over twice the speed of the 4 Series Express.
