AMD FidelityFX Super Resolution 2.1 Promises Better Upscaling And Less Ghosting
by
Zak Killian
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Thursday, September 08, 2022, 04:47 PM EDT
AMD's FidelityFX Super Resolution (FSR) is a method by which video games can reduce their render resolution (and thus, the GPU workload) and then upscale the lower-resolution input to the higher output resolution of the display. The company's been working on the tech non-stop, and the latest version promises to address some of the shortcomings of FSR 2.0.
Despite being called "2.0", FSR 2.0 is really a first-generation temporal upscaler, because the original FSR 1.0 was simply a spatial upscaler, little more than a screen filter. With that in mind, it's really no surprise that the "2.0" revision would still have some faults, and further, that AMD would work to correct them.
The biggest problems with FSR 2.0 had to do with the way it handled rapidly moving objects. You see, 3D games are simulating spaces in three dimensions, but your display is only two-dimensional. This means that, just like real life, sometimes objects near to the camera block your view of objects far from the camera. This is called "occlusion," so naturally, when an object becomes visible because something in the foreground moved (or because the camera moved), this is called "disocclusion". Hold that thought.
FSR 2.0, as well as NVIDIA's DLSS and Intel's XeSS, are known as "temporal upscalers" because they are using input data from multiple frames to do their work. Essentially, as part of the process of generating pixels to fill in the gaps in the upscaled image, they rely on data from previous frames to know what colors to use to fill in said gaps.
FSR 2.1 (right) cleans up the ghosting left behind by the combine's sprayer.
When objects move quickly or erratically, however, they are likely to quickly reveal areas that were occluded in previous frames. This leads to what we call "disocclusion artifacts," where the upscaler has no information on what should be in the "gaps" because the objects revealed were not visible in previous frames.
Another Farming Simulator 22 comparison. 2.0 left, 2.1 right.
Compared to NVIDIA's solution, FSR 2.0 had more problems with disocclusion artifacts. We didn't check for such in our brief informal pre-release testing, but other outlets noticed the issues and reported on them thoroughly. The artifacts don't ruin the experience by any means, and FSR 2.0 is still a great upscaling solution, but they can be distracting during gameplay.
Well, AMD says that FSR 2.1 goes a long way toward resolving said artifacts. Through myriad changes, detailed in the chart above, AMD says that it has alleviated a significant portion of ghosting and disocclusion issues. The company offers up a YouTube video and some comparison screenshots for your pixel-peeping pleasure, which we've reproduced here.
FSR 2 hasn't seen quite the same adoption as DLSS yet, but NVIDIA's technology had more than a year head-start. AMD says that the implementation of FSR 2 should take "five minutes" if your game already supports DLSS, and we suspect that's probably true for games that are using XeSS as well. All three techniques seem to use more-or-less the same input data to do their magic.
However, it's not like FSR 2 is being ignored. AMD offers this list of 45 games, including 20 released games and 25 upcoming titles, that offer support for the upscaling tech. FSR 2 has the advantage of not requiring dedicated AI hardware, so it can run on essentially any graphics processor. We're curious to see for ourselves if FSR 2.1 finally matches up to DLSS, so look for another investigation of the techniques in the future.