If you have a small amount of ram and the game requires more ram than what you have then it will store the information on the hard drive because it can't go anywhere else. Say your ram runs at 533 mhz effective clock speed. That has a maximum theoretical transfer rate of 4200 MB per second while your hard drive has according to blue 30 MB per second so that's like 140 times faster if it doesn't have to swap to the hard drive. So if u want some good performance make sure you have a lot of ram. How much do you have anyway? O ya 30 mb per second is probably your substained transfer rate it will be much slower because of seek times.