I recently got some cheap cards for mining - Sapphire Nitro+ RX480 with 4GB of Elpida memory which was originally clocked at 1750MHz.
As Polaris Editor doesn't work with Elpida cards, i started fiddling around with the Hexeditor and managed to copy the 1500MHz memory timing straps to the higher ones.
Now my test card is running smoothly @ 29+MH/s while drawing only 77 Watts over the PCIe lines while clocking @ 1145/2050MHz
Feel free to test my BIOS at your own risk.
All modding was done with switch on "silent mode" (towards the connector plate).
Use atiwflash as usual.
edit: files now external.Edited by Aleistermarley - 10/13/16 at 7:20am