NVIDIA's latest tech will more than double path tracing performance

Full ray tracing or path tracing is still a relatively new frontier in gaming, with the realistic cinematic lighting mode opening the door to a new level of immersion in games like Cyberpunk 2077, Alan Wake 2, DOOM: The Dark Ages, and Resident Evil Requiem. It's incredibly demanding on hardware, significantly more so than single-use ray-tracing effects like reflections or shadows, and it's widely considered the future of AAA in-game visuals.

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One of the most challenging elements of path tracing, as it covers all ray-traced lighting effects, is global illumination, with NVIDIA's latest technology to accelerate and improve fidelity and performance called ReSTIR (Spatiotemporal Importance Resampling PT). Without getting into the technical weeds, NVIDIA's Research team just released a paper on ReSTIR PT Enhanced, which "significantly" improves performance, produces fewer artifacts, and enhances visual fidelity.

Path tracing is so demanding that it requires additional help from DLSS Super Resolution, Ray Reconstruction, and Frame Generation to deliver smooth gameplay. Based on this new paper (which you can check out as a PDF here), ReSTIR PT Enhanced improves path-tracing performance by over 2X.

It achieves this through several optimizations and clever techniques that reduce data duplication by performing complex calculations for every pixel. It also unifies ReSTIR for both direct and indirect lighting while implementing new technology that adapts to the scene and the materials present. The paper ran its tests on a GeForce RTX 5080-equivalent workstation card, which isn't the top-of-the-line RTX Blackwell GPU for gaming, so it's a good sign that NVIDIA isn't targeting its top-end hardware for path tracing.

As ReSTIR PT is part of the RTX SDK and available to developers, the good news is that, even though this is a research paper, NVIDIA notes that this update is "closer to production-ready."