I don`t know how exact you can adjust memory access to GPU memory, but ppl that compare and cry here thet RX 4xx should be fast as 390x should first learn that any architecture is different, the driver is accessing GPU memory as best as it can, if zcash need many small accesses and if 256bit bus is not wide enough its logical that 384 or 512bit bus will be better, even when we know with 2xx and 39x GPU and memory clock is more "aligned" and in sync then on RX cards which usualu work 11xx/2000

CRYING here RX4xx is pointless if you know NOTHING about internel GPU arhitecture and even less about zcash prof of work algo and how its computed