I am planning on upgrading memory on 2 ASUS mobos. A7N8X-X and A7N8X-E. Both have 3 DDR "The motherboard has three Double Data Rate (DDR) DIMM sockets that supports up to 3GB non-ECC PC3200/2700/2100/1600 DDR" I am guessing that the 3GB limitation is a Windoz limitation. Tom