gtx 1080ti or rtx 2080ti?

Solution
There will be improvement, I am sure of that.
The point is currently more about the improvements (aside from the new features) and the price increase.
Moreover, ray tracing and stuffs will be hard to find in games within the first years. By the time those features become mainstream (if they can even go mainstream and don't just die like PhysX, etc.), your RTX 2xxx should be already outdated.
There will be improvement, I am sure of that.
The point is currently more about the improvements (aside from the new features) and the price increase.
Moreover, ray tracing and stuffs will be hard to find in games within the first years. By the time those features become mainstream (if they can even go mainstream and don't just die like PhysX, etc.), your RTX 2xxx should be already outdated.
 
Solution

boju

Titan
Ambassador
Dice had to dial back ray tracing to keep a reasonable frame rate of 60fps. There will be potential improvements from both sides (Nvidia and game devs) as time goes on but without ray tracing i don't think 1080Ti will be beat by much.