Arriving in the evening before we were due to tape DF Direct Weekly #257, Bethesda and Sumo Digital have proven true to their word, adding DLSS upscaling to the already impressive Fallout 4 port for Nintendo Switch 2. In replacing the existing TAA with its associated blur, DLSS should be the dream ticket in making a good conversion even better, but the improvement turns out to be a little more modest than we hoped. There is a boost to image quality and performance - albeit limited - but the core bottlenecks in the game remain as-is, with DLSS failing to bring the game-changing improvements many might have hoped for.

So, on paper then, DLSS is added to two of the three modes in the game - the 40fps and 60fps options. Fallout 4 is intriguing in that the quality settings for each mode are entirely the same - the only difference comes from the how dynamic resolution scaling interacts with the chosen frame-rate. The higher the frame-rate, the lower the average resolution, obviously.

But here's the thing: while we can see DLSS-like characteristics to the 60fps mode, we don't see much of any difference between the new 40fps option and its immediate predecessor. Side-by-side captures including aggressive 4x zoom comparisons reveal the same overall image quality, right down to identical aliasing patterns and flickering characteristics.

Resolution remains unchanged, with both 40fps and 60fps modes operating in a 720p-1440p dynamic resolution window. The 40fps mode was pretty solid at launch, to be fair, so either we're looking at a conservative implementation or more likely that DLSS is not yet active in the 40fps mode.

The 60fps mode definitely has changed, however. Fallout 4 on Switch 2 historically struggled to achieve and sustain the target frame-rate, but it turns out that DLSS is not the complete solution here. Dense city environments like downtown Boston are still highly CPU and/or memory bandwidth limited, resulting in erratic frame-times and a spiky presentation that can take you into the 40s and even 30s - though there is some evidence that the stutters may have been marginally reduced. The new patch seems to give you a 2-3fps uplift in GPU-limited scenarios, however.

There are changes to image quality though, with some aliasing reduced, but we also noticed that there are some areas where pixel break-up seems amplified compared to the prior TAA solution. This makes us think that if there is DLSS involved, it's the "tiny" DLSS variant designed for higher performance, but lacking the more complete upscaling package provided by the convolutional neural network (CNN) model as seen in titles like Cyberpunk 2077 and Resident Evil Requiem.

That's not ideal and we can't help but wonder whether dropping resolution to save GPU cycles and to use the "full fat" CNN DLSS available on Switch 2 might have been the preferable option. That said, for the "lite" DLSS to provide any kind of performance uplift over the standard TAA is quite the feat.

One interesting technical wrinkle is the handling of UI elements - specifically the Pip-Boy. The patch notes indicate that DLSS disengages when the Pip-Boy is active in order to preserve text clarity. In practice, this transition is subtle enough that it is difficult to spot during normal play, which suggests a careful transition occurring behind the scenes. More obvious are changes when transitioning to menus or loading screens, the changes in scaling paths are easier to perceive.

Taken as a whole, Fallout 4's DLSS update essentially offers an incremental improvement to an already impressive package, as opposed to a game-changing transformation. DLSS itself turns out to be a nice addition as opposed to a magic bullet that mitigates all performance and image quality compromises. The improvement is best seen when docked, as the handheld modes still look rather murky. But with that said, by having a "before and after" scenario between TAA and the lighter form of DLSS, we've learned just how lightweight the pared back version of Nvidia's upscaler is in terms of its computational cost - something we could only have guessed at before.