- AMD’s FSR 4 performance is slightly weaker than FSR 3, based on new FidelityFX SDK 2.0 demo test
- The performance difference is only 5%, which isn’t significant, but can be at much lower frame rates or weaker GPUs
- FSR 4 may still be the best choice for RDNA 4 GPU users
AMD’s FSR upscaling technology has come a long way in delivering excellent performance and visual quality, with the leap from FSR 3 to FSR 4 serving as proof of that, especially on one of the best GPUs on the market – but there’s a catch.
New FidelityFX SDK 2.0 tests from tech enthusiast Osvaldo Pinali (opinali on X) showcase FSR 4’s tax on performance in gaming compared to FSR 3. Using the Radeon RX 9070 XT in an FSR demo, FSR 3.1.5 provides 290 fps, while FSR 4.0.2 achieves 276 fps.
The new SDK (software development kit) expands FSR 4 support with increased developer access for game integration, which also briefly saw FSR 4 go full open-source before AMD removed it from GitHub – which points at Team Red’s efforts of porting FSR 4 back to older GPUs.
Without veering off point, Pinali essentially discovered that FSR 4 has 37% higher GPU utilization, likely due to its machine learning (ML) based AI functionality. However, the frame rate difference between FSR 3 and FSR 4 in the FidelityFX SDK 2.0 test is only 5%, which simply isn’t significant enough to hinder performance in games.
FSR 4’s visual quality improvements over FSR 3 are arguably night and day; it’s not as good as Nvidia’s DLSS 4 offering, but it’s a great alternative, and has already surpassed DLSS 3 in terms of its super-resolution quality.
Where the 5% difference may have a slightly bigger impact is with weaker RDNA 4 GPUs, or in games that are demanding to run, which have much lower average frame rates.
In the sample I can pick the FSR version. With FG off, vsync off:9070 XT, FSR 3.1.5: 290fps9070 XT, FSR 4.0.2: 276fpsRTX 5080, FSR 3.1.5: 356fpsUpscale time is FSR3.1=0.51ms, FSR4=0.70ms. FSR4 costs +37% GPU; still a small fraction of total frame even for this simple demo.🔚August 23, 2025
Analysis: if AMD can backport FSR 4 to older GPUs, it could be a stronger Nvidia DLSS 4 alternative
There’s no denying that Nvidia is in the lead in both the GPU market and upscaling tech. DLSS 4 is available on all RTX GPUs and does a fantastic job of ensuring image quality is great, even when using its performance modes.
While FSR 4 does a similar thing coming from FSR 3, the problem is that it’s not enough to directly challenge DLSS 4, and FSR 4 is exclusive to RDNA 4 GPUs. This comes down to ML-based technology and advanced AI hardware in RDNA 4, but if it becomes available on older hardware, Team Red will place itself in a better position up against Nvidia when it comes to upscaling.
I’m using an Nvidia GPU, so this doesn’t quite affect me, but it will be interesting to see how a potential backport of FSR 4 will impact RDNA 3.5 iGPUs on handheld gaming PCs.
