I tried to mod bios but now Windows does BSOD when installing blockchain drivers.
Try installing the latest 17.12.2 Adrenalin drivers. After it installed you can set the Compute mode in the settings.
Radeon settings -> Gaming -> Global settings -> Per GPU - Compute mode
Also how did you mod? Did you download the BIOS from your card and edit that? Could be that the changes are too high for your card and when it initialises it crashes.