Red Dead Redemption 2 is a 2018 action-adventure game developed and published by Rockstar Games. The game is the third entry in the Red Dead series and is a prequel to the 2010 game Red Dead Redemption. Red Dead Redemption 2 was released for the PlayStation 4 and Xbox One in October 2018, and for Microsoft Windows and Stadia in November 2019. (Wikipedia).
Engine: Rockstar Advance Game Engine (RAGE). We test by manually selecting Ultra settings (or High where Ultra is not available), TAA, Vulkan API.
As for Red Dead Redemption 2, the differences between the RTX 3080 Ti and RTX 3090 are increasingly small in this title, to the point where we measured the same average frame rate between the two at 4K. This is the only game where this happened, but it does go to show we are talking about the finest of margins between the two Ampere GPUs.