AMD FidelityFX Super Resolution Image Quality Investigated

[harlan4096]

Upscaling and sharpening for everyone, but mind the image quality.

AMD released its FidelityFX Super Resolution to the public today, along with a new 21.6.1 driver, and we've been testing it via early access for the past few days. Hailed as Team Red's alternative to DLSS, but with open arms to embrace all GPUs, many hoped for a better universal upscaling and enhancement solution. FSR does what it promised—faster performance by rendering at a lower resolution and then upscaling—and it ran on every recent GPU we threw at it, but there's more to discuss than raw performance improvements. Specifically, we wanted to focus on image quality to see whether FSR can match DLSS 2.0.

Let's start with a quick overview of what the algorithm does. Upscaling lower resolution content and then applying a sharpening filter is something that has been done for quite some time. Early Blu-ray players and HDTVs would 'enhance' 720x480 DVD content, and modern 4K players can do the same for 1080p content. Depending on the amount of sharpening, the results can range from good to "oops, that's too much" to where you see halos on all the edges. AMD's FSR tends to land closer to the 'good' end of the spectrum, at least at the higher quality settings.

The FSR algorithm has two components. First, it does an upscaling pass to a higher resolution, with an edge detection component that works to generate a good result—better than bicubic filtering would be the goal. Then it applies a sharpening filter, and from what we can tell, this is basically just AMD's existing CAS (Contrast Aware Sharpening). CAS on its own at native resolution looks quite good most of the time, and it's relatively lightweight. So the combination of spatial upscaling combined with CAS should provide decent results, as long as you don't push things too far.

FSR Scaling Factors and Resolutions
FSR Preset Scale Factor 4K Input 1440p Input 1080p Input

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Ultra Quality 1.3X 2954x1662 1970x1108 1477x831
Quality 1.5X 2560x1440 1706x960 1280x720
Balanced 1.7X 2259x1270 1506x847 1130x635
Performance 2.0X 1920x1080 1280x720 960x540

The scaling factor ends up being the critical component, and it's important to remember that it applies in both dimensions. 1.3X upscaling isn't just 23% fewer pixels to render; it's 41% fewer pixels. In performance mode, the game only has to render 25% as many pixels before applying the upscaling and sharpening filters, which naturally provides a large boost to performance in most games.At Ultra Quality, FSR looks quite close to native rendering (without CAS, if the game supports it), and even Quality mode looks quite close to the original. But as you'd expect, the more upscaling that takes place, the more artifacts you'll notice, and the Balanced and Performance presets definitely represent compromise—and we'd say the same for DLSS in Performance mode.

Let's move over to image quality comparisons for FSR and DLSS now, and we'll scramble the order and provide a guessing game of sorts (with answers at the end). At present, we had access to five games with FSR (Anno 1800, Godfall, Kingshunt, Riftbreaker, and Terminator: Resistance). Two other games should have FSR patches available today, 22nd Century Racing Series and Evel Genius 2. Besides those seven games, AMD lists 12 more games that will be getting FSR support "soon": Far Cry 6, Resident Evil Village, Forspoken, MYST, Dota 2, Necromunda Hired Gun, Baldur's Gate, Swordsman, Farming Simulator 22, Astergos, Vampire the Masquerade: Blood Hunt, and Edge of Eternity. Some of those aren't even out yet, but hopefully Far Cry 6 has FSR enabled at launch.

AMD also notes that over 45 games now have one or more FidelityFX elements enabled. That's slightly behind the more than 55 games that now come with DLSS, and of course, many of the games with FidelityFX aren't using FSR right now. But over time, particularly considering the AMD hardware in the PlayStation 5 and Xbox Series S/X, we should see more games adopt FSR. But how does it look?
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