Accompanying the Portal RTX news above come new GeForce Windows drivers for NVIDIA graphics cards. This page has a full article about this release. These are required to run the update to Valve's puzzle game. In addition, they add support for an upcoming DLSS 3 update for Jurassic World Evolution 2 and a next-gen update coming to The Witcher 3: Wild Hunt. Here's a new The Making of Portal with RTX Video. Here's more:

Game Ready for Portal with RTX!
NVIDIA has reimagined Valve’s iconic video game Portal, widely regarded as one of the best video games of all time, with advanced graphics features such as advanced ray tracing, NVIDIA DLSS 3, NVIDIA Reflex, and more, to give the game a striking new look and feel. Portal with RTX is available now as a free, official downloadable content (DLC) for the classic platformer.

Game Ready for The Witcher 3: Wild Hunt’s Next-Gen Update!
On December 14th, all The Witcher 3: Wild Hunt PC players will receive a free update that adds various gameplay changes, new quest content, and new graphics features that take full advantage of the latest PCs and laptops.