if vbios mod than best way cmd style on all gpus after the last one restart:
atiflash -f -p 0 newvbios.rom
atiflash -f -p 1 newvbios.rom
.
.
.
atiflash -f -p 5 newvbios.rom

AMD DRIVER:
1. if vbios mod than on exisiting amd driver via cmd (atiflash)
2. restart
3. uninstall amd driver in safe mode with GuruDDU
4. install new amd driver, before restart apply atikmdag patcher
5. restart
6. you are ready.

DAG fix beta driver undervolt problem:

Hey I had the exact same issue with my rx470. After 10 hours of trying I finally found out what was wrong. The problem is with AfterBurner - you need to uninstall it before replacing old drivers with new ones.
So the correct procedure is:
1. Uninstall MSI Afterburner
2. Uninstall drivers with DDU in safe mode
3. Install the freshly-downloaded driver from setup
4. Before restart install and run the atikmdag patcher
5. Install Beta MSI Afterburner (I installed latest 4.4.0 beta16)
6. Restart and tweak your rig

And you should be ready to mine at full speed again Cool

Personaly for me the difference is from 131 Mh/s to 138 Mh/s with power use rising from 400w to 460w.
