fully updated windows 10?
blockchain drivers?
do those first then BIOS mod/overclock..should be around 24 stock
I have RX 570 4GB Sapphire Pulse OC on stock settings 24.7 Mhsh and I have same memory as you, Hynix. Totally underperforming, try updating the drivers to latest ones (latest drivers have already the blockchain driver incorporated into them, as long as the number of the driver is 17.10 or above). Also try to change risers, 6 pins risers are better than 4 pin molex sata risers, they give more power and are more stable.
Thanks for your input! So I did a clean up of my old driver and installed the blockchain driver which gave me about 22.5MH/s mining Eth on claymore. Further I modded the card where I copied the 1750 timing at 2000 and now am getting 25.2MH/s. Have to yet work on Over clocking this thing. But still don't you think i should have achieved about 27Mh/S after I did the modding and should reach about 30MH/s after over clocking it?
Modding isn't just about copying lower memory timing straps into higher ones. Try experimenting with custom timings using SRB Polaris Editor.
There are many great threads in this section where people have discussed Polaris' timings in length. You'd benefir greatly from this.
Also this may be obvious make sure you set the memory clock above 2000, or otherwise it won't use the modified straps.