Quick answer: NVIDIA released RTX Remix 1.6 on October 23 with DLSS 5 3D-Guided Neural Rendering, up to 6X Multi Frame Generation, Windows on ARM support and a beta Minecraft Java Edition mod, and Portal with RTX and the Half-Life 2 RTX demo were updated with the same features.
NVIDIA's RTX Remix modding platform hit version 1.6 on October 23. The headline addition is DLSS 5 3D-Guided Neural Rendering, with live controls in the Toolkit so modders can tune the effect in their scenes. The update also adds 5X and 6X Multi Frame Generation on supported hardware, the faster Frame Generation Performance Mode (Preset C, still in beta), and a sparse rendering option that leans on DLSS Ray Reconstruction to trade some image quality for speed.
Remix 1.6 also runs natively on Windows on ARM, with NVIDIA naming RTX Spark as an example, and it raises the minimum NVIDIA driver to 616.92. On the creation side, the old AI tools were replaced with a ComfyUI-based workflow for textures and meshes.
The two showcase remasters already have the new runtime. Portal with RTX was updated on Steam on October 21, and the Half-Life 2 RTX demo followed on October 23 in an update from Orbifold titled "DLSS 4.5, ARM Support & Rendering Improvements." Both add optional 3D-Guided Neural Rendering (off by default), Frame Generation Preset C for RTX 40 Series, RTX 50 Series and RTX Spark laptops, 5X and 6X Multi Frame Generation on RTX 50 Series cards, Windows on ARM support and shadow fixes. Neither update adds new levels. Press Alt+X in-game to open the RTX Remix settings, and the options you see depend on your GPU and driver.
There's also a new beta: RTX Remix for Minecraft, a Fabric mod that path traces Minecraft Java Edition 1.21.1. NVIDIA's requirements are Windows 10 or 11, a GeForce RTX 30-series or newer GPU with driver 616.92 or later, and about 5GB of free space during install. NVIDIA says it has had limited testing with other mods and only targets version 1.21.1.