A Review of Nvidia’s DLSS 4 Multi Frame Generation

DLSS 4 Multi Frame Generation is the latest technology Nvidia is using to market and sell gaming graphics cards. Exclusive to the new GeForce 50 series, including the RTX 5090 we recently reviewed, Multi Frame Generation is an evolution of frame generation technology that we’ve examined before.

Instead of generating one frame for every rendered frame, Multi Frame Generation allows up to three frames to be generated – so essentially, it’s just more frame gen…

DLSS 4 Includes More Than Just Multi Frame Gen

Now, Multi Frame Generation is just part of Nvidia’s DLSS 4 technology suite, but it’s the focus of this article because it’s the only component exclusive to the RTX 50 series.

DLSS 4 also includes updates to single frame generation, super resolution upscaling, and ray reconstruction, featuring upgraded models for better performance and image quality. However, those are not exclusive to the latest GPUs – these improvements to DLSS also work on existing GeForce RTX hardware.

In other words, you don’t need a GeForce RTX 50 series card to use most components of DLSS 4. In fact, the image improvements in this iteration of DLSS – going from a convolutional neural network to a vision transformer – likely provides the biggest improvement to DLSS since Nvidia introduced version 2.0 of the feature in 2020.

Having that said, Multi Frame Generation is the one feature Nvidia wants users to think is worth upgrading for and what they are using to claim dramatic performance boosts in this new GPU generation.

Multi Frame Generation is the one feature Nvidia wants users to think is worth upgrading for and what they are using to claim dramatic performance boosts in this new GPU generation.

We plan to cover other updates to DLSS 4 upscaling, ray reconstruction and single frame generation separately in future articles – but today we want to focus on the new multi frame gen feature to see how much value it’s bringing to the 50 series, and where it makes sense to use. We’re going to explore image quality, latency and FPS output in this review, so all of the usual good stuff.

The problem with testing Multi Frame Generation (MFG) is that it’s designed with high frame rate gaming in mind. At a base render rate of 60 FPS, Multi Frame Generation in its top mode will produce 240 FPS – well above what can be shown in a 60 FPS video sample on YouTube. And that’s without even considering whether a base render rate of 60 FPS is sufficient.

On top of this, capturing 240 FPS for visual analysis is not easy. There are no capture cards available that can capture 4K or 1440p at 240 FPS; this option is only available at 1080p, which isn’t a realistic use of the technology.

Locally capturing 240 FPS is also very challenging. We tried several solutions, but ultimately, at 1440p or 4K, it’s impossible to locally capture 240 FPS in a stable manner where every frame is accurately captured. Adding a second GPU to offload the encoding work didn’t help either – it’s just not feasible.

Unfortunately, this means for the visual analysis of Multi Frame Generation, we are effectively limited to 4K 120 FPS capture. This requires a base render rate of 30 FPS, a configuration we absolutely do not recommend and one that doesn’t showcase frame generation in the best light. However, this is how Nvidia recommends demonstrating the visual quality of Multi Frame Generation, so if it’s good enough for them, it’s good enough for us.

You’ll also see a lot of footage that’s slowed down because even 120 FPS can’t be displayed on YouTube. To make sure you can actually see every generated frame and what they look like, we’ll have to slow the footage down. Ideally, we’d create a 4K 240 FPS video to provide a real-world representation of the technology, but that’s not possible due to current hardware and platform limitations.

As we head into the visual analysis, we want you to keep a few things in mind:

• We do not recommend using frame generation at a base render rate of 30 FPS, even though some footage was captured this way.
• Capturing footage this way, and then slowing it down for display in a 60 FPS YouTube video, exaggerates the artifacts in the frame generation output.
• Please pay attention to the commentary where we describe how visible these issues are in real-world content displayed on a high-refresh-rate 4K 240Hz monitor. The footage in this article serves as a demonstration to highlight how frame generation impacts each frame.

How Does DLSS 4 Multi Frame Generation Work?

With DLSS 4 Multi Frame Generation, Nvidia’s algorithm generates up to three intermediate frames between two traditionally rendered frames. This process uses interpolation technology, meaning it relies on rendering two base frames and then creates additional AI-generated frames to fill in the gaps between them. These generated frames are inserted to improve motion fluidity and reduce latency, making the visuals smoother.

Importantly, this is not extrapolation, which predicts future frames; instead, it interpolates based on already-rendered before-and-after frames to maintain accuracy and consistency in the output.

DLSS 4 brings other improvements to frame generation: the optical flow pass has been replaced with an AI optical flow model, and with that, Nvidia claims performance improvements and a lower memory footprint. However, these improvements are accessible on both RTX 40 and RTX 50 series GPUs. So, all comparisons in this article, whether we’re looking at single or multi-frame generation, are using the new DLSS 4 version. Again, we want to focus on the benefits that 50 series owners are getting.

Speaking of that, Nvidia explains that multi-frame generation is not available on older GPUs because the Blackwell architecture includes a new capability called hardware flip metering, which is required for smooth multi-frame generation output. We have no way of verifying whether that’s true or what the experience would be like with multi-frame generation on a 40 series GPU without it – but hey, exclusive features are good for business.

Multi-frame generation (MFG) will be accessible through two methods.

Some games will have native support for multiple frame generation modes, allowing users to choose between 2X, 3X, and 4X modes. These modes generate additional frames beyond the original single-frame generation experience, with the 4X mode quadrupling the FPS output. The modes are labeled based on the FPS output increase, but it’s important to note that this is not considered a performance increase.

Another method to enable multi-frame generation is through a DLSS Override in the Nvidia App. The majority of games that support DLSS 4 do so through this method, where the Nvidia App swaps the DLL for you. However, this is a whitelist system, so only games on the list can use the Override.

To use the Override, users can select the frame generation mode they want in the graphics settings for a game in the Nvidia App, such as 3X or 4X modes. When in the game, enabling frame generation will switch to the selected mode instead of the default single-frame generation. While this method is not as seamless as native game support, it still allows for the use of multi-frame generation.

In terms of image quality analysis, multi-frame generation enhances smoothness in predictable scenarios but may introduce artifacts in complex or unpredictable scenes. The technology is most effective in high-framerate environments with simple movements, but may struggle with fine details and fast-paced actions. Artifacting becomes more noticeable at lower base render rates and in demanding scenes, making it a mixed experience depending on personal preference.

Benchmarking FPS and latency with multi-frame generation shows an increase in FPS output but a potential regression in latency compared to native rendering. Enabling multi-frame generation can improve FPS output but may increase latency due to the additional processing required. It’s important to consider the trade-offs between increased frame output and potential latency issues when using multi-frame generation technology. Using MFG 4X with a frame rate of 120 FPS results in latency over four times higher, making the game feel much slower, akin to a 30 FPS experience. Nvidia’s comparison of the RTX 5070 to the RTX 4090 based on FPS output fails to acknowledge the significantly worse latency in the configuration with more frame generation, which is misleading.

In various games like Star Wars Outlaws, Cyberpunk 2077, and Hogwarts Legacy, enabling multi-frame generation saw an increase in frame rate but also an increase in latency. While render rates improved, latency also worsened, affecting the overall gaming experience.

Although Nvidia claims that there isn’t much latency penalty from generating additional frames, the reality is that there is overhead associated with creating extra frames, leading to lower render rates and higher latency compared to single-frame generation.

Multi-frame generation can be beneficial in certain situations, providing smoother gameplay and better utilization of high refresh rate monitors. However, it also comes with potential drawbacks such as increased artifacts and latency costs. The technology works best at a high base render frame rate, maintaining the quality of the experience linked to the actual render rate of the game.

For optimal gaming experience, it is recommended to start with a frame rate of 100 to 120 FPS to ensure smooth, clear, artifact-free, low-latency gameplay. Enabling multi-frame generation may lower the render rate but increase the output frame rate, offering a trade-off between performance and visual quality. Having a good experience with multi-frame generation (MFG) depends on the frame rate and latency you’re comfortable with. For single-player gaming, a frame rate of 85-100 FPS is good for minimizing artifacts and latency. If you’re less sensitive to latency, a starting frame rate of 70-80 FPS is recommended for multi-frame generation. However, going below this can result in a bad experience with noticeable artifacts and a rubbery feel.

When comparing DLSS 3 (SFG) to DLSS 4 (MFG), it’s important to consider the style of game and input method. Frame generation typically requires a higher render rate for first-person games, faster-paced games, and mouse and keyboard users. Multi-frame generation may not provide as significant of an improvement as single-frame generation, especially for those with high refresh rate monitors.

Overall, the usefulness of MFG on the GeForce RTX 50 series may be limited, especially for those with mid-range setups. Nvidia’s marketing of DLSS 4 as a technology that drastically improves FPS may not align with the practical benefits for many gamers.