Hi, i was disappointed when i got my new RTX 5080 only to discover this game doesn't work anymore because of the severe graphics glitches and the frame generation being totally broken and have not seen the dev of this mod addressing the situation so i took matters into my own hands and figured out how to update the RTX Remix version this game uses to the latest version from NVIDIA meaning the game now has all the options from Portal RTX in the menu that appears when you press "Alt-X"

You need to go to https://github.com/NVIDIAGameWorks/rtx-remix/releases and download the "remix-1.1.0-release.zip" and once you have that you just open the .zip and copy and paste the "d3d9.dll" that you see in the .zip file into the "steamapps\common\Portal Prelude RTX\bin" folder and overwrite the original.

You then have to delete the ".trex" folder that is inside of the "steamapps\common\Portal Prelude RTX\bin" folder and copy and paste the ".trex" from the "remix-1.1.0-release.zip" you just downloaded to replace it.

After you have done this you need to download a program called "DLSS Swapper" from "https://github.com/beeradmoore/dlss-swapper" and once it finds Portal Prelude RTX you need to swap the "DLSS", "DLSS Frame Generation" and "DLSS Ray Reconstruction" to v310.3 which is the latest version available as I write this. If you see a newer version that is higher than v310.3 then use that instead.

Finally you need to right click on the game in the Steam Library select "properties" and add "-console -default" to the launch options and wait for the game to load up the title screen. You will see a dev console appear with some errors but just ignore this and close the game. Go back to the Steam Library, right click the game and select "properties" again then remove "-console -default" from the launch options.

Now when you start the game and press "Alt-X" you will see in the menu that you now have the latest version of DLSS with the Transformer model option available AND fully working 2x, 3x and 4x Frame Generation available!