I recently got a Sapphire RX 470 Nitro+ and made sure my drivers were up to date, and I can't play Fallout 4 at all without it crashing. Windowed mode works but I keep getting 1 fps when customizing my character and from there on. Bethesda support seems to be stumped and I've already gone through many of their troubleshooting procedures. Likewise, the launcher says it can't recognize my GPU. I uninstalled the integrated graphics drivers and shut off the integrated GPU in my bios. The only other game that doesn't work is the Witcher 2 which always crashes on startup, other than that everything is working fine.
Some more INFORMATION REQUIRED WHEN POSTING A QUESTION may help.
Links to your Beth./Steam posts (for FO4), so we don't repeat already suggested fixes.
What related error messages from Windows reliability history.