We compared FSR 4 and DLSS 4 for the first time a few weeks ago. We did so at 1440p, concluding that FSR 4 was a solid upscaling tech. It’s a big step up from FSR 3.1 and often outperforms Nvidia’s DLSS 3 although the newer DLSS 4 still takes the lead. How does it perform at 4K? Today, we’ll explore this.
It is important to examine upscaling in different output resolutions because the quality of upscaling can vary greatly between 1080p and 1440p. Upscaling algorithms are fed more data at higher resolutions. This results in a better output.
With FSR 3.1, for example, Quality mode upscaling was often usable at 4K but looked rough at 1080p. So, we’re interested to see how FSR 4 performs under the most favorable conditions for the technology.
The Radeon RX9070 XT was used to capture all the FSR 4 samples in this article at 4K, while the GeForce RTX5090 was used to capture the DLSS samples. We selected a number of games that had settings such as motion blur, film grains, vignette and chromatic Aberration disabled.
Sharpness has been set to 0 in order to upscaling. All DLSS 3 samples were updated to DLSS 3.8.10 except for Hunt: Showdown which remains at DLSS 3.7 because it cannot be upgraded. All DLSS 4 samples are using the latest version available via Nvidia’s driver override. Let’s get started.
FSR 4 vs FSR 3.0 at 4K
FSR 4’s improvement over FSR 3.1 was one of its most impressive features. The new AI-based upscaler is much better at this resolution, even if you compare the Quality modes. The gap becomes wider when comparing performance modes. The improvement FSR 4 makes at 4K is more nuanced because FSR 3.1 already made it easier to use. Check out the HUB below for a better representation and comparison of image quality.
The difference between FSR 3.1 and FSR 4 is still noticeable at 4K in Quality mode. We believe that most gamers will be able to recognize the improvement FSR 4 offers. The improvement is not as dramatic because some of the artifacts in the FSR 3 1440p footage have been reduced.
FSR 3.1’s 4K Quality mode may appear slightly grainy, especially in areas such as hair and transparencies. However, this is not as bad as 1440p where these elements are often broken or distracting.
FSR 4 offers a sharper, more detailed image than FSR 3.1. Transparencies are cleaner, hair is rendered with greater accuracy, and there is less shimmering.
The image stability of some of the most problematic FSR 3.1 titles, such as Ratchet & Clank Rift Apart, has been significantly improved with FSR 4. FSR 4’s output has a more authentic 4K feel. FSR 3.1, however, still looks like it is running at a lower quality resolution despite its “4K” output.
When comparing Performance modes, the difference is even more obvious. FSR 3.1 struggles to maintain its Performance mode, even at 4K. FSR 4 is much more stable and less grainy. It’s also quite usable in many situations. If you used FSR 3.1’s Quality mode at 4K previously, switching to FSR 4 Performance mode is likely to be an upgrade for most situations. This is how far we’ve come. Check out the HUB below for a better representation on image quality comparisons:
This can be seen in a clip of Spider-Man 2 which shows how FSR 4 allows better performance on the new RDNA4 cards under realistic, playable circumstances – because you can now use FSR 4 Quality instead of FSR 4 Performance.
FSR 4 vs DLSS Texture Quality
In this article, we will compare FSR to DLSS as that is where the most interesting battle takes place. FSR 4 easily outperforms FSR 3.1. However, just as we found at 1440p there is a lot of nuance to how FSR 4 compares against DLSS 3, and DLSS 4 We won’t be going through all the examples from the 1440p comparison, but we will focus on a few to see if those findings are still valid at 4K. Check out the HUB below for a better representation on image quality comparisons:
As seen at 1440p and FSR 4, both FSR 4 as well as DLSS 4 have the ability to reduce or even eliminate motion blur that is associated with TAA. This benefit is also carried over to 4K.
FSR 4 looks less impressive in comparison to DLSS 4 at this resolution. FSR 4 in the Quality mode looked better than DLSS 3 at lower resolutions, and was often somewhere between DLSS 3 to DLSS 4 when viewed. DLSS 4 looks better at 4K. FSR 4 looks closer to DLSS 3 in similar examples.
According to us, this is because blurring caused by TAA-based technology is less noticeable in 4K than 1440p. DLSS 3 is a good example of this. The difference between moving and still images becomes smaller at higher resolutions. DLSS 4 maintains texture quality exceptionally well. FSR 4 isn’t quite at that level but, even under less favorable conditions, the texture detail matches or exceeds DLSS 3. This is true for both Performance and Quality modes.
Although it may not match DLSS 4 in terms of clarity and sharpness, FSR 4 offers a strong performance when gaming at 4K. FSR 4 is a great option for gamers who play on 4K displays. It addresses the blurring issues that were seen with earlier AMD upscalers.
Performance mode, for example, is now quite useable in terms texture quality. It delivers results that are close to Quality mode, when it comes to reducing TAA – something that we previously would not have recommended at any time.
FSR 4 vs. DLSS: Image stability
FSR 4 performs better in 4K than at 1440p when it comes to image stability. During testing at 1440p, FSR was sometimes less stable that DLSS 3. In some strange cases, Balanced mode provided more stability than the Quality mode. This inconsistency is gone at 4K. Check out the HUB below for a better representation.
FSR 4’s image stability is usually on par with DLSS 3 in Quality mode. FSR 4 may not have the same rock-solid presentation as DLSS 4, but it still has a very usable quality. There is no significant increase in shimmering compared with DLSS 3. The higher resolution also makes it easier to see visual artifacts such as shimmering and sizzling, which improves overall image stability.
We found that the stability levels of the Quality and Balanced modes were similar or slightly in favor Quality mode, unlike at 1440p where Balanced sometimes behaved more well. Artifacts such as the aliasing of brick textures in The Last of Us are no longer visible or even completely gone at 4K. This results in a cleaner image, which improves the competitiveness of DLSS. This improved stability is also beneficial to tricky elements such as grates and meshes. FSR 4 is quite good here. We even observed instances where it handled these elements better than DLSS 4 in some cases. This is probably due to FSR 4, which exhibits fewer disocclusions artifacts. We noticed this at 1440p and it’s also present in 4K.
. The degree to which these effects can be seen depends on the game and the quality settings.
FSR 4’s performance mode impressed us as well. It often provided greater stability in motion compared to DLSS 3. This puts it somewhere between DLSS 4 and 3.
DLSS 4 offers the highest-quality and most stable image, but FSR 4’s performance mode is now more useable than DLSS 3’s. This is a significant accomplishment. FSR 4’s Performance or Balanced mode is easy to justify depending on the game. This was not possible with FSR 3.
One of the main drawbacks of lower FSR 4 modes, is that they lose fine detail. These modes can smooth out or eliminate subtle textures to maintain stability. This is most evident when compared to DLSS 4 which retains both fine detail and stability. FSR 4 is still able to reconstruct fine details at 4K but the cleaner image will be achieved by using the higher quality modes.
FSR 4 renders transparencies better than FSR 3, and this is true even at 4K. FSR 4 now matches DLSS in handling effects such as holograms and flames – it’s not the garbled, blurry mess that older versions were.
Both particle effects and rain look great at this resolution. When compared to DLSS 3 or 4, snow in Horizon Zero Dawn, for example, looks great, even in Performance mode. Scenes that looked painful before using low FSR settings now look much better.
FSR 4 vs DLSS – Foliage Quality
Lastly we looked at the foliage quality. FSR 4 produces excellent grass at 4K. It falls between DLSS 3 & DLSS 4, just like it did at 1440p. FSR 4 looks less grainy in some games, such as Ratchet & Clutch and Hunt: Showdown when using the Quality mode. In some games, such as Horizon Zero Dawn the results are very similar to DLSS 4. Check out the HUB below for a better representation.
Previously we were of the opinion that FSR 4’s tree stability was worse than DLSS 3 despite a sharper picture. This issue is less pronounced in 4K, as overall stability has improved. FSR 4’s rendering of trees now matches DLSS 3 in worst-case scenarios. This is a good result, though DLSS 4 delivers the best upscaling.
FSR 4 is slightly more stable with fine details like thin, leafless limbs, but this can sometimes come at the expense of fine detail.
Both in Quality and Performance modes this holds true, proving that FSR 4 is a solid performer even at lower settings.
Performance
There’s nothing new in terms of FPS performance that wasn’t covered in the analysis for 1440p. We tested FSR with the RX 9070 XT, and DLSS with the RTX5070 Ti – they both deliver similar performance or at least as near as we can get to the current GPU lineups.
Four identical games were tested with the same settings as in the previous comparison, but this time the focus was on the geometric average of the results.
The performance trends at 4K are similar to those at 1440p. FSR 4 provides a performance boost comparable to DLSS 4.
FSR 4, in Quality mode, showed a performance improvement of 35% over native TAA for the 9070 XT. DLSS 4, Quality mode, delivered a gain of 31% on the 5070TI. Performance mode was slightly faster than Balanced mode on the DLSS 4.
Although both upscalers require a little more overhead, the improvements in visual quality that FSR 4 and DLSS 4 offer over FSR 3 and DLSS 3 are worth it.
What We Learned
It was expected that AMD’s FSR 4 would be more stable at 4K compared to 1440p. This allows it to match or even outperform DLSS 3 under most circumstances. FSR 4 was a little behind Nvidia’s last-gen upscaler in some instances at 1440p. However, this is much less likely to happen at 4K.
FSR 4 is a solid middle ground between DLSS 3 & DLSS 4 in terms of image quality. FSR 4 is very competitive. While DLSS 4 is more stable and detailed – with an even sharper display than at 1440p – FSR 4 has now become very competitive, particularly for those who had previously considered DLSS 3 ( “good enough.”
Also, we see a significant upgrade from FSR 3 to FSR 4 in 4K. The image detail and stability are much improved when using the Quality mode, and the difference is night and day using the Performance modes. If you found FSR 3.1’s Quality mode acceptable for gaming in 4K, you will likely find FSR’s Performance mode to be a significant upgrade. It’s that good.
FSR 4’s Quality or Balanced mode will be a great option for most players across a variety of games. While Performance mode isn’t as good at 4K as DLSS 4 equivalent, it’s still a great option for those who want more FPS. FSR 4’s Balanced mode is now a valid option, while the Quality mode has been improved.
FSR’s Game Support is Still Behind
AMD has done an excellent job of bringing FSR 4 up to par, but there are still concerns about the game support. AMD must now accelerate adoption in order to match DLSS 4’s reach. This will be a major factor in choosing between Radeon or GeForce GPUs for the foreseeable. DLSS is supported in more titles and it would be unreasonable to expect FSR 4 games to receive hundreds of updates immediately.
What has been frustrating is the slow rollout for FSR 4 updates in games that should have already supported it. AMD must whitelist games in their driver in order to enable the FSR-3.1 to FSR-4 upgrade toggle. This should ideally happen in day-one drivers. Unfortunately, this hasn’t happened, leaving Radeon users with the 9000 series without immediate FSR 4 compatibility in major releases.
- Assassin’s Creed Shadows, for example, launched with FSR 3.1. It should be eligible to receive FSR 4, but the support is still lacking. DLSS 4 was also available from day one through Nvidia’s driver-override.
- Kingdom Come Deliverance II, a FSR 4 title, was announced when AMD revealed the feature. However, it still lacks support even though it uses FSR 3.1. DLSS 4 already works in this game.
- Indiana Jones and the Great Circle cannot be upgraded to FSR 4 because it uses Vulkan which FSR 4 does not yet support – however, this limitation does not apply to DLSS 4
AMD says they validate FSR 4 before enabling them in drivers, but let’s face it – day-one support is essential. These checks should be done before launch and driver updates should add new titles regularly. The latest driver version 25.3.2 supposedly added AC Shadows support, but it didn’t include FSR4 driver upgrades, which is a critical feature.
If AMD is able to streamline game support, and release timely driver updates, that enable FSR 4 by 2025 releases, then they will be in a good position to compete on the upscaling market, especially since FSR 4 upscaling works well at 1440p and 4K with various quality settings.
