I have 6x sapphire rx 570 8gb micron memory , I don't do bios mod but only change the core clock and memory clock to be :

core clock = 1280

memory clock : 2170


same thing I have 1x msi rx 570 4gb elpida memory

core clock = 1280
memory clock =2110 ( I try increase to be 2140 but not working and restart my rig )

I do that  more 1 month ago and it's work good and give me in eth hash = 26.5 MH per card  , someone tell me my afterburner setting is too high and it will be damage your cards , are this is true ?