What algorithms/coins rely more on mem clock than core clock?
According to my observation all dagger-hashimoto coins depend on memory speed very much!
So that is why all rx card are flashed with modded bios which allow to achive more speeds
for example - without modded bios RX570 pushes like 22.5--24.5 mh/s, but with that bios it can achieve 28.5-31 mh/s ( depends on the memory type and brand)