On these gaming machines, it doesn't matter much. The game will use ram while it loads and frees it up when it unloads. Since you can only run one game at a time, having more than 4GB is not going to help at all. A home PC is a different kind of thing, since it can actually run more things at once, but slot games are not designed to use a whole lot of memory (they don't really do much). Most of us max it at 4GB just because, but when you view the memory usage on the machine, you will note that most of the memory is just sitting idle.