In the manual, the 2 slot listings for 1600 and 1800 are for XMP DIMM installation recommendations. I hope that things will work out as wished. We should find out soon though. I also have P5E3 premium and QX9770 but unfortunately the 4x1gb will have to wait a bit (mobo being RMAed). Puttz, let us know how things turn out after you get things up and running.