This mod has been updated with RTX Remix.

Nvidia announced and released Portal: Prelude RTX, a remaster of a 2008 mod. This update includes updated visuals, support for raytracing, DLSS 3 support, and is the first game to publicly use RTX I/O.

Raytracing and DLSS 3 are both rather self-explanatory as several games have come out featuring these technologies already. RTX I/O stands for RTX Input/Output and is a new way for your GPU to reduce the load times for large amounts of data such as game assets and textures. It's essentially Nvidia's implementation of DirectStorage 1.2, similar to the tech that will be used in the PC release of Ratchet & Clank: Rift Apart.

Portal: Prelude RTX is still very much a free release, but you will need to own Portal in order to play this fancy new release. You will also obviously need a GPU capable of actually running these fancy technologies.

Portal Prelude and the new Portal: Prelude RTX serves as a prequel to the events in the original Portal.