anyone here who has xfx rx570 4gb blck edition elpida ram?

copied 1:1500 till 1:2000

made my hashrate  25- to low 26.xxx . but i cant oc may memory clock more then 1800

my rx 570 powercolor red devil 4gb(hynix) can make it to 1900mhz+ around 27-28mhs

are all xfx rx570 like this or someone here made it more than 26mhs?