Make sure you're using the latest DLSS dll's from NVIDIA, makes a WORLD of difference. My first attempt with DLSS (with an RTX4090) was miserable and I was wondering what all the hype was about, and having buyers remorse on that card. I happened across some other forums that suggested using the latest DLSS from NVIDIA directly, and it is night and day!
There are lots of download sites out there, but I chose to get mine straight from NVIDIA.
https://developer.nvidia.com/rtx/dlss/get-started