DLSS 4.5 presets M and L show denoiser interaction issues in ray-traced content
Digital Foundry found an unusual behavior in NVIDIA’s DLSS 4.5 Super Resolution. In testing, DLSS 4.5 presets M and L produced cleaner ray-traced reflections when the games’ own denoisers were disabled. The pixel hunting team mentions examples like Crysis 3 and Silent Hill 2, where disabling the built-in denoiser reduced “boiling” and blur in reflections.
Ray-traced effects often start from sparse samples, so developers run denoisers to suppress noise and temporal instability. Those filters can also soften detail, which is why reflections sometimes look smeared.
Source: Digital Foundry
This matters because DLSS Ray Reconstruction was introduced in DLSS 3.5 as an AI denoiser intended to replace multiple hand-tuned ray tracing denoisers. The DLSS 4.5 behavior is happening without Ray Reconstruction, and says Ray Reconstruction has not been updated for the newer DLSS 4.5 model yet.
On the one hand, this means DLSS is a better denoiser than some games’ standard denoisers – which is kind of funny – but on the other hand, it means DLSS preset M and L have issues when overlayed after stock denoising. That is problematic as we want image reconstruction to be as plug and play as possible without these issues and without having to effectively mod games, but also, we probably want titles to implement things like DLSS Ray Reconstruction anyway.
— Digital Foundry
Source: Digital Foundry
For users who want to test it, NVIDIA says DLSS 4.5 Super Resolution can be enabled through the NVIDIA app using “DLSS Override – Model Preset” on a per-game or global basis. NVIDIA’s “Recommended” setting maps Preset M to DLSS Performance mode, Preset L to DLSS Ultra Performance mode, and Preset K to the remaining modes. Digital Foundry shows exact commands you need to run in tested games to disable the game’s built-in denoisers.
Source: Digital Foundry
