With the settings below, I think you will have a great experience playing Red Dead Redemption 2. These settings mimic the graphics settings on High/Ultra presets with minimal FPS loss, trading off some visual settings that are not worth the FPS loss while preserving similar visuals. From my experience, this should give you over 65% boost to your FPS compared to Ultra/High presets, as my PC with an old 4.1GHz i7 3770, 16GB RAM and GTX 1070 pretty much runs this at a constant 60 FPS at 1080p with minimal dips during gameplay.

PSA: Update your Nvidia / AMD graphics card drivers before running the game and understand you need to have similar specs to my PC and my resolution in order to get decent FPS

Screen Type: Fullscreen
Texture Quality: Ultra
Anisotrophic Filtering: 16x
Lighting Quality: Medium
Global Illumination: High
Shadow Quality: High
Far Shadow Quality: High
SSAO: Ultra
Reflection Quality: Medium
Mirror Quality: Ultra
Water Quality: Medium
Volumetrics: Medium
Particle Quality: Ultra
Tessellation: Ultra
TAA: Medium
FXAA: OFF
MSAA: OFF

Advanced Settings: Unlocked
Graphics API: Vulkan
Near Volumetric Resolution: Low
Far Volumetric Resolution: Medium
Volumetric Lighting Quality: High
Unlocked Volumetric Raymarch Resolution: ON
Particle Lighting Quality: Medium
Soft Shadows: High
Grass Shadows: Medium
Long Shadows: ON
Full Resolution SSAO: OFF
Water Refraction Quality: Medium
Water Reflection Quality: High
Water Physics Quality: Half
TAA Sharpening: Any setting you want, I like to leave it at max
Motion Blur: OFF
Reflection MSAA: X2
Geometry Level of Detail: 3/5 [slider bar setting]
Grass Level of Detail: 4/10 [slider bar setting]
Tree Quality: High
Parallax Occlusion Mapping: Ultra
Decal Quality: Ultra
Fur Quality: High
Tree Tesselation: OFF

This result is recorded with the in-game benchmark tool.


Note: My GTX1070 is OC'd at +100 to Core and +500 to Memory on the latest drivers from Nvidia. Your results may vary.

The above settings are taken from Hardware Unboxed. Please subscribe to them if you enjoy their content! They make great content and their video goes into detail what you need to configure if the above settings aren't good enough in your eyes. Part 2 of their video may also help you further by enabling async compute (if your GPU supports it) and other settings.