So the performance on GPUs are decreasing over the time?
what gou you have? up to 3gb gou are not suable anymore, and the 4gb will be soon over too, because ETH have a diff boom that increase regardless of mining and the dag files is getting bigger and bigger, so you can't mine with old gpu anymore
I am using AMD Sapphire, Power color, ect.. 4gb RX470, RX480, RX570, RX580. Mining using Claymore. So this is normal? or just the GPU performance?
This is normal for those cards. You will expect 30% mining performance reduction for those cards in the next few months.