TECH

How to mod NVIDIA DLSS 5 neural rendering into unsupported games for a huge FPS lift

A developer has vibe-coded a new ReShade add-on file that offloads the DLSS Neural Rendering workloads to a second GPU, almost negating the otherwise massive DLSS NR performance hit. Given the original DLSS 5 shots we saw when Jen-Hsun first showed off the feature around GDC and GTC in the Spring were running on two graphics cards, that's not wholly surprising, but this mod certainly does open the the potential for keeping your old GPU around for neural coprocessing in the future.

Like almost all of the current DLSS 5/Neural Rendering implementations we've seen where the user gets to pick the game, the model, and the weight of the effects, the Neural Coprocessor add-on file—mgpu_bridge—is designed for ReShade, an app used to inject different visual effects into PC games. The files exist on Github, can be downloaded and added into a game that's already been modded with DLSS 5 support, and could dramatically improve the performance.

This is, for me, the biggest issue with both the homebrew mods for DLSS Neural Rendering and the only release implementation we've seen from Nvidia and the developers themselves: the hefty performance penalty from turning it on.

Nvidia itself has touted a 50 - 60% frame rate hit as a blanket figure—regardless of game and how much AI filtering it's doing—as what it is expecting to see from enabling DLSS NR. Andy benchmarked NBA 2K27 ahead of launch and found that sometimes the frame rate impact can be even higher than that.

I mean, it's not as bad as when you try and run DLSS NR on AMD GPUs, but I've noted these kinds of performance hits when you run the new feature through ReShade, too. But Marcelo Guibout has coded a ReShade add-on file that allows a second GPU—here an RTX 5060 Ti 16 GB—to take the final finished frame and perform the neural rendering pass on that GPU and output on its own monitor. That means it doesn't have to hand the frame back, which adds its own performance hit and latency.

If you read that headline and you thought "wait, I thought DLSS 5 hurt your FPS", you're right. The idea here is that NBA 2K27 has been updated with the new DLSS 5 Neural Rendering that NVIDIA announced prior to the RTX Spark platform launch, and folks have been replacing the old library with the new one for a big performance lift with very minimal changes in image quality.

There are reports all over X about this; the most convincing is probably this one from Detro (@detro_official) where he compares Judy with the old DLSS 5, the new DLSS 5, and without DLSS 5 on an RTX 4080 SUPER. With the old version his upscale was taking 8.8ms; with the new version, just 5.4ms. His frame rate jumps from 108 FPS to 150 FPS, although we should note those numbers are with 4x multi-frame generation, so the actual frame rates are 27 FPS and 37.5 FPS. That's still a 39% uplift, which is massive for a DLL swap.

The two shots do look a bit different; that could be down to differences in the new model, but it could also potentially be down to a shift in the time of day. That's the reason given for the difference in looks between these two shots from Forza Horizon 6, by Gaming Optimized (@GamingOptimiz):

The performance is again, relatively low—jumping from 27 FPS to 37 FPS—but it's only a GeForce RTX 4060 card. In that context, it's actually quite impressive that the GPU manages to pull out 37 FPS average with DLSS 5 enabled in Forza Horizon 6! That same user posted a comparison in Resident Evil 9, as well:

There's definitely some image quality difference between the older and newer model, as Resident Evil 9 does not have a dynamic time of day system like the others. However, the difference is decidedly minor, and that's incredibly impressive considering how much faster the new model is. If NVIDIA can continue making gains like this, it's possible that Neural Rendering might become mainstream.

Of course, that depends entirely upon the game you're using it with, and whether its art style suits the photorealistic look of DLSS 5 NR. For example, I personally don't particularly care for the effects of DLSS 5 NR on Judy's face in Cyberpunk 2077 (top). However, for games that are less stylized (like NBA 2K27), it definitely gives a wild uplift in the visuals, and this performance gain is absolutely welcome.

If you want to try this out for yourself, it's not exactly a straightforward process. You're going to have to download ReShade (the Addons version, which makes it unsuitable for online games), and join the RenoDX Discord to grab the modified version that allows you to inject DLSS 5. You'll also need the new version of the DLL, currently hosted on X here, although who knows how long that will stay up. Once you have those, put everything into the same directory with the game executables, and then when in-game, press the "Home" button (by default) to customize the effect. There's a more detailed guide in the RenoDX Discord, so head over to their website if you want to join.

 

by mundophone