NVIDIA DLSS 4.5 Ray Reconstruction Review – Transformer Improved

Introduction

Earlier this year NVIDIA rolled out DLSS 4.5—the big headlines were Dynamic Multi Frame Generation, 6X Multi Frame Generation and a second-generation transformer model for Super Resolution. One piece was still missing from that release: Ray Reconstruction, which continued to use the first-generation transformer model that shipped with DLSS 4. Today NVIDIA is closing that gap with the release of DLSS 4.5 Ray Reconstruction, which brings with it an improved denoiser aimed at everything that uses ray tracing or path tracing.

Ray Reconstruction was first introduced with DLSS 3.5 in 2023 (our review), and the idea behind it hasn’t changed since. During ray tracing, only limited number of rays is cast per frame, far fewer than there are pixels on your screen, which means this output alone would be full of noise. Traditionally, a hand-tuned denoiser cleans up that noise, and only once that is complete, the upscaler runs on this output—at that point all the information from the game engine about rays, light and materials is gone. Ray Reconstruction replaces the classic denoiser with an AI-powered model that is trained for this specific purpose, and it merges denoising and upscaling into a single pass. This pass has access to a lot of more data, too, so it can produce a better result (at least theoretically).

What’s new today is the model behind it. According to NVIDIA, the second-generation transformer model processes 20% more parameters and delivers 35% more…