AMD FidelityFX Super Resolution – Finally competition for Nvidia’s DLSS?

AMD FidelityFX Super Resolution is AMD’s answer to Nvidia’s DLSS technology. Both solutions render the image at a lower resolution and then upscale it to a higher resolution and sharpen it in a smart way. Both technologies try to guarantee the image quality in this process as much as possible, but each does this in its own way. Nvidia uses Tensor cores for its AI algorithm calculations. This means that only video cards with support for this hardware acceleration can use it. In practice, this means that GeForce RTX cards are required, DLSS is not supported on older GTX cards.

AMD is taking a completely different route with FidelityFX Super Resolution, or FSR. This technology, officially made public on GPUOpen as of today, uses conventional GPU cores to perform its calculations. This means that FSR can be used on a variety of video cards from past generations, both from AMD and Nvidia. According to the manufacturer, the FSR algorithm has been developed in such a way that it requires as little computing power as possible. This statement immediately makes it clear that the strength of FSR, its flexible applicability, is also its weakness. Competitor Nvidia can fully load the Tensor cores to get the best results from smart upscaling without sacrificing gaming performance.

How does FSR work?

Similar to DLSS and other upscaling techniques, such as checkerbord rendering, FSR works by rendering images at a lower resolution and then upscaling them to the desired resolution. Because this input resolution is lower, the frames to be rendered are ready faster and the frame rate is higher than when rendering at a higher (native) resolution. This can be useful for graphics-heavy games, especially to correct for the performance impact that ray tracing entails. Nvidia reasons in a similar way; the final image quality would be higher when ray tracing is enabled and DLSS is used than when traditional rasterization is used at native resolution.

The available quality settings for FSR are divided into four categories: Ultra Quality, Quality, Balanced and Performance. Depending on the chosen preset, a fixed, lower input resolution is used and then upscaled. With Ultra Quality, the number of pixels per dimension is still about 77 percent of the final resolution, with Performance mode it’s only 50 percent.

Because FSR has the input resolution lower, this also reduces the image quality by making the image less sharp. FSR aims to bring back those details thanks to an advanced recovery algorithm, AMD said. Edge detection analyzes and sharpens parts of the original image, followed by an overall sharpening pass . The computational power required to upscale images with FSR is minimal compared to the computational power required to render images natively at a higher resolution. In almost all cases, you should therefore be left with a higher frame rate without having to make significant sacrifices in image quality, is the idea.

Hardware and games support

AMD emphasizes FSR’s openness by showing that the technology also works on Nvidia video cards, including older GeForce cards dating back to the GTX 1000 series. In the case of Nvidia’s video cards, AMD notes that Nvidia itself has to add support in the drivers in order to use FSR on GeForce cards, and that AMD has only tested this as a proof-of-concept on a few competitor cards.

FSR, like DLSS, requires the integration of the technology into games by game developers. That is not the case with Radeon Image Sharpening, an existing contrast-dependent upscaling technology. It was only able to upscale and sharpen every completely rendered image, which has the advantage that any game running in DirectX 11, 12 and Vulkan can be used by RIS, so no game-specific support needs to be built in. However, FSR is more advanced than RIS in that it runs in the graphics pipeline after any anti-aliasing, but before other effects, such as film grainand also for placing hud elements. In addition, FSR in the pipeline consists of several passes, allowing for more precise steering towards the desired end result without introducing too many visual artifacts.

AMD says it’s making it as easy as possible for developers to integrate the technology into their games through developer toolkits, support and collaboration. Together with the fact that FSR will be made accessible to every developer via GPUOpen, the manufacturer hopes for a fast and high adoption in existing and future games.

First experiences with FSR

Shortly before this article we were able to test FSR ourselves in a few games: Godfall, The Riftbreaker and Terminator Resistance. The test system used consists of a Radeon RX 5700 XT as a video card and an Intel Core i5 8500 as a processor. All tested games were provided with a special beta patch to support FSR, as well as the Radeon Software 21.6.1, which is available to everyone as of today.

In all three games we tested, we were able to enable FSR from the in-game menu without having to exit or restart the game. The user can choose the different presets, which allowed us to make a comparison with the screenshots below. We used two screen resolutions for this. The figures shown in the tables are the lowest average frame rates we saw during these comparisons, so should be used as an indication rather than a strict benchmark.

1440p

On a screen resolution of 2560 by 1440 pixels, it is easy to see when FSR is turned on. With the Ultra Quality preset that is not so bad and during gameplay it is actually not noticeable. If you stop for a comparison, as we have done with our screenshots below, it will start to become clear from the Quality preset that you are losing resolution. This can be seen over almost the entire image as a somewhat blurry presentation. This is offset by a much higher frame rate.

It differs a bit per game where the disappearance of details is the first visible. In Godfall we see the film grain become much stronger with each preset of FSR that prefers a higher frame rate over image quality. In The Riftbreaker, it is mainly certain plants and trees that look less sharp, while everything with sharp edges comes out better. With Terminator, the image is even sharper on Ultra Quality than on native resolution, but on Balanced and Performance it is a lot more blurry.

The gain in frame rates with FSR varies per game and per preset. Terminator Resistance gains the most in our comparison, while The Riftbreaker makes relatively modest gains.