Days Gone received a free official patch. It runs via backwards compatibility at a dynamic 4K resolution at a rock-solid 60 FPS . Simply update the game to the latest version to enable this.
Ensure your graphics drivers are up to date. While Days Gone doesn't have native DLSS, you can use Lossless Scaling (available on Steam) to add frame generation to the game. Performance Settings:
This is the most popular "downloadable" boost. It modifies the game's internal configuration files to optimize CPU/GPU usage beyond what the in-game menu allows.
The PC community has developed several tools to help lower-end systems or those aiming for high refresh rates.
On consoles, "FPS Boost" is a built-in system feature rather than a file you download.