This is what exactly I'm gonna do i have rx 570 4gb sapphire nitro+ and i bios modded and it runs 31.2mhs on ethereum without rejected shares and i want that bios again on the 8gb rx 570 sapphire nitro+ too what do you think will be the best way to run 8gb rx 570 like my rx 570 4gb?
The hash rate in mining is increased by optimizing memory timings. Video cards have different memory: samsung, micron, hunix.
For each memory, you need to flash your timings to get an increase in the hashrate.
Understand what memory you have on each video card and modify your BIOS.
https://www.techpowerup.com/gpuz/