Horse lag

[Smurfington]

not sure why but horses lag like crazy when riding

 

[Theodore Baggins]

Which server are you on? Do they lag more than when riding a motorcycle? There are many things that can cause you to drop frames or seem to teleport backwards or forwards. The majority of them are client-side (i.e. your computer and not the server). Your setup may be fine - but settings like render distance and ambient occlusion (in addition to the quality settings) can make a big difference in my experience. 

However, it's important to know that, while Rust has been optimized heavily over the last couple years, it commonly eats 20GB+ of RAM and all 12GB of my graphics card's VRAM on High settings. I've tuned a specific overclock for my Titan Xp for Rust and I still sometimes experience frame drops or "cinematic" frame rates, even if the total GPU load remains relatively low. For me, it's my processor and RAM that are showing their age—not my graphics card—so the settings that work for me won't necessarily work for you.