Are you talking about the level streaming? Whenever you enter an area, it has to stream in and that's going to cause hitching regardless of your system.
If it is streaming, it is taking its sweet time, as I have loaded an area and started moving 3 minutes later and had it still chunk while I turned. it seems to be fine once I turn all directions but has a hard time with the initial look around. This only happens on the big maps, like Detroit and whatnot.