Why not just a simple google search with: sapphire rx 580 nitro+ 4gb elpida bios mod. You might be able to find something... C/P 1500 strap up to 2000 are not optimal at all but should gives you some good gains. A perfectly edited vbios have a price cause it have takes hours from developer to test and improve, so almost no already edit vbios you could get for free are perfectly tweaked, but for free you can't complain. Tonnes of basic tutorials are available on YouTube to learn how to mod your vbios. Have only 1 Amd with elpida and using the simple C/P trick have got some decent results, take a look on page 2 of this thread, you might find something good for Elpida mem, but haven't test it yet. If I see an improvement using this strap, might be able to assist you a lil more with it.