AMD Fidelity FX Super Resolution (FSR) is an image scaling technology in modern 3D games that allows you to increase performance with minimal loss in the quality of the final image. Having appeared on the market last year, the technology is rapidly gaining support in an increasing number of game projects. What is it and how does it work? We will tell in this article.
What is scaling
Image scaling is an integral part of the visual digital content we consume. This applies to both photos and videos, as well as 3D games. The screens of the devices we use – computer monitors, laptops, TVs, smartphones and tablets – often do not match the resolution of the content that is played on them. And here scaling comes to the rescue. In the case of a photo, it reduces the size of the content to the device screen resolution, in the case of a video, it can either reduce or enlarge the original image to the native resolution.
With regard to games, both options are also possible. Rendering at a higher resolution and reducing it to the target greatly increases the quality of the picture. But at the same time, it requires too many resources and is practically unsuitable for modern games. In this case, only old projects can show good performance. And vice versa – rendering at a lower resolution and restoring it to the target one will help the video card show much better performance in modern projects with minimal loss of quality.
Why their scaling methods appeared in games
In cases with photos and videos, quite simple methods are enough. But with regard to the 3D image of modern games, the resources of equipment and algorithms that will be used for high-quality scaling require much more. The simple scaling method usually applied to video is bilinear and is not suitable for games. Because the picture in this case is too blurry.
This led to the creation of special scaling methods for 3D projects that combined several different methods to keep the final image crisp. The first such hardware-software method was Deep Learning Super Sampling (DLSS) from NVIDIA, which was released in 2019.
NVIDIA technology combines software scaling methods with hardware scaling methods only available on RTX family cards. The so-called tensor cores, which use machine learning technology, after scaling the picture, “finish” the missing details based on previously studied examples. The picture quality of the first version of the technology did not shine, but already in the second version by the end of 2019 it improved noticeably.
The technology has two drawbacks. The first is that RTX cards are required for use. Neither older cards nor AMD cards have this technology available. Second, the technology must be supported by the game engine. To date, only a few popular engines can boast of its support.
Competitor DLSS – FSR technology, AMD introduced last year. The main task of the technology was to make it possible to work on any video cards, including old competitor cards, and even integrated graphics. For FSR, specialized blocks of cards with ray tracing support are not used. Its goal is to work on any cards that support modern graphics APIs: DirectX and Vulkan.
In addition, unlike DLSS, integrating the technology into the engine is as simple as possible. FSR can be easily added even to old projects if their developers would like to. And although the overall quality of FSR is often slightly lower than DLSS, the ease of implementation and support for more equipment contributes to a much more widespread adoption of the technology.
Why FSR is needed
The main goal of FSR is to increase performance in games while maintaining sufficient quality of the final picture. Modern games are heavy enough for budget and outdated video cards, and in 4K resolution at maximum settings, not all of them obey even flagships. In addition, games with ray tracing squander performance even more, making it sometimes uncomfortable even on expensive cards.
The goal of FSR is to address this shortcoming by making it possible to play at higher graphics settings at the target resolution. Flagships get access to games at maximum settings without drawdowns in higher resolutions. And budget and outdated cards – the ability to play without “brakes” those games in which they were previously on the verge of playability.
How FSR works
When FSR is enabled, the image displayed on the screen goes through the following steps:
Rendering of a 3D scene is performed at a lower resolution relative to the screen.
The image is stretched to the target resolution using an open source scaling algorithm.
The image obtained after scaling undergoes post-processing. It also increases the overall clarity, sharpness of edges and contrast.
Elements of the game’s interface in the original resolution are superimposed on the final image.
After completing all the steps, the picture is sent to the user’s display device. FSR currently has four quality settings, each with a different ratio of render resolution to screen resolution.
The highest quality – Ultra Quality, uses a factor of 1.3.
The Quality mode, which is not much inferior in quality, has a coefficient of 1.5.
Balanced mode is limited by a factor of 1.7.
The most productive mode is content with a factor of 2.0.
Rendering resolutions in different FSR modes at popular screen resolutions are presented in the following table:
Performance and quality
So what performance improvement can FSR offer in games? Let’s take Godfall as an example.
In the case of a modern flagship in high resolution and with ray tracing, the difference is literally amazing – in Performance mode, the frame rate increases by more than 100%. And even in the highest quality Ultra Quality mode, the increase in frame rate is at least 50%. At lower resolutions, the performance of the card is excessive, so the corresponding effect is leveled.
In the case of using a mid-range card from 2016 in Quad HD, the increase is also quite noticeable. In fact, thanks to FSR, the resolution of 2560 x 1440 turns from unplayable into comfortable to use. In popular Full HD, this is not observed, but you can still count on an additional 25-50%, depending on the mode.
But what about quality? Let’s look at the example of the game Marvel: Avengers. In Ultra Quality mode at 4K resolution, the difference with normal rendering and competing DLSS is almost imperceptible.
In Balanced mode, the quality is worse, but in 4K you can only see the difference in static. At lower resolutions, the difference will increase, but in dynamics it will still be possible to observe a decent picture.
Distribution and future prospects
More than 60 game developers and publishers have supported the use of the technology in their games. More than two dozen projects with FSR support are preparing to launch. The technology is already being used in more than 50 game projects. Among them:
FSR is currently supported by all AMD graphics cards from the RX400 series and up, as well as NVIDIA 1000 series and up. Since the source code of the technology is open, enthusiasts have already found a way to make it work on older cards, and even on integrated Intel graphics. AMD also built a similar RSR (Radeon Super Resolution) technology into its card drivers, which does not require support from the game engine to work. It can be used in older projects without FSR support.
Current generation consoles and the upcoming Steam Deck also support FSR. Since the technology is purely software, the list of possible hardware that can receive its support is huge. In the future, it may expand its presence in the market through applications in mobile devices.