My system is very similar to yours, just a little lower (R5 1600 @ 3.8, RX480 8GB, 16GB @3200). I have good performance with this settings, but on 1080p. And have anti-lag turned off on Radeon settings. I have much better performance using windowed mode and vsync off, letting windows DWM handle the tearing. Try it.
If you want, you can tell me an exact location, weather, and time, so we can compare performance. Good luck.
PS. I have multiplayer and AI turned off, don’t care about them, so don’t know if that affects performance.