For a visual walkthrough on how to further boost your frame rates and fix persistent lag in Black Flag, check out this guide:
: Disable this entirely unless you have a high-end NVIDIA card, as it is a primary cause of stuttering. Fixing the 60 FPS Cap and Stutter 1440x900 Thoughts: Assassin's Creed 4 – Black F...
: This is the most intensive setting. Dropping it from "Very High" to "High" can provide a massive frame rate boost. For a visual walkthrough on how to further
: Set these to "Low" or "Off" . The "High" setting consumes considerable resources for a visual effect that is often distracting. : Set these to "Low" or "Off"
resolution is less demanding than 1080p, allowing for higher settings on mid-range hardware.
: In your NVIDIA Control Panel or AMD Catalyst , go to "Adjust desktop size and position" and set scaling to "Fullscreen" rather than "Aspect Ratio".
Because the game natively supports 16:9, users on 16:10 monitors like yours frequently encounter letterboxing.