The reduction in die size, in order to get a chip of such a configuration down to the mainstream price points, is also probably the primary reason that a 256-bit memory bus is not utilised. Whilst transistor sizes scale down with new processes, the pads (chip to packaging interconnects) do not similarly scale down, hence 256-bit buses actually require a large die size in order to facilitate all the connections and the die size of RV410 may not be large enough to facilitate such a bus.