XBOX Series X Runs FSR 4 Faster Than Radeon RX 6700 XT

AMD's FidelityFX Super Resolution 4 (FSR 4) offers a critical image-quality upgrade to XBOX Series X and S. However, early performance testing has produced a surprising result: the XBOX Series X can run FSR 4 faster than a PC graphics card with more theoretical computing power. Digital Foundry's findings highlight Microsoft's hardware and software optimization and show how console-specific innovation can deliver strong performance without specialist AI hardware.

XBOX Series X Beats Radeon RX 6700 XT in FSR 4 Testing

When Microsoft introduced FSR 4 support for XBOX, it also released a sample application developers can run on both XBOX and PC. The demo features a palace environment with fog, particles, and a T. Rex, letting developers switch between FSR 3, FSR 4, and FSR 4 Light.

Digital Foundry's Rich Leadbetter tested the PC version using an AMD Radeon RX 6700 XT, one of the closest PC equivalents to XBOX Series X. Both use AMD's RDNA 2 architecture, making them suitable for comparison. The test ran at 4K using Balanced mode and the full FSR 4 model designed for RDNA 2. Balanced mode renders internally at approximately 1270p before reconstructing the remaining image.

The Radeon RX 6700 XT required approximately 5ms per frame, occasionally reaching 5.2ms. Microsoft's published figure for XBOX Series X was just 3.86ms. That means the console completed the workload considerably faster.

Sharpening produced another difference. Enabling it increased processing time on the RX 6700 XT to approximately 5.5ms, around 10% more. On XBOX Series X, the increase was only around 4%. FSR 4 Light also performed better on XBOX, requiring 2.75ms compared with 3.11ms on the RX 6700 XT.

Why Microsoft's FSR 4 Optimization Matters

The comparison becomes more interesting when considering the hardware specifications. The RX 6700 XT has 40 compute units running up to 2.58 GHz, while the XBOX Series X has 52 compute units running at 1.825 GHz. The PC graphics hardware is about 13 TFLOPS versus the console's 12 TFLOPS. It also leads in theoretical INT8 computing performance, offering around 53 trillion operations per second compared with XBOX's 49 trillion.

Even with those benefits, the RX 6700 XT is roughly 30% slower to process FSR 4. It's about the hardware architecture and the software optimization. FSR 4 was originally designed for newer AMD graphics cards using dedicated AI hardware and FP8 calculations. The XBOX Series X lacks those dedicated accelerators, so AMD adapted the technology to use INT8 math through its regular graphics cores.

Interestingly, Microsoft anticipated these workloads when designing XBOX Series X. In 2020, Microsoft's Andrew Goossen explained that many AI algorithms could operate using 8-bit and 4-bit integer mathematics. Microsoft consequently included specialized hardware support for these calculations.

XBOX also benefits from 560GB/s memory bandwidth, compared with 384GB/s on the RX 6700 XT. Combined with console-specific optimization, this helps explain its impressive performance.

FSR 4 Could Improve XBOX Series S Image Quality

Another essential aspect is memory usage. Digital Foundry observed roughly 318MB of FSR 4 memory consumption at 4K, and 81MB at 1080p on PC. These numbers are on par with FSR 3, so the new technique shouldn't put too much strain on memory.

The FSR 4 on XBOX Series S is ~1.9-2.9ms at 1080p depending on the model chosen. That's a bigger chunk of the console's GPU power, but it might deliver serious visual benefits.

Games running at 30fps have approximately 33ms per frame, while 60fps titles have less than 17ms. For 60fps modes, Digital Foundry expects developers to target 1440p internal resolution, where FSR 4 costs approximately 1.3-2ms on Series X.

GTA 6 Could Reveal FSR 4's Real Potential

The next challenge is seeing FSR 4 implemented in actual games. Data miner Tez2 reportedly discovered AMD FidelityFX upscaler files in the XBOX version of GTA 6. However, the encrypted files also support FSR 3, so there is no confirmation that Rockstar will use FSR 4. GTA 6 will target 30fps on consoles; therefore, FSR 4 could focus on improving visual sharpness rather than frame rates.

Ultimately, Digital Foundry's testing points to a much more complex Microsoft solution than a simple console port. Better image quality might come to XBOX Series X and Series S through specialist INT8 hardware, memory bandwidth, and software optimization without the need for new hardware. The real test will be when devs start implementing FSR 4 into big games.

FAQ

Q. Why does XBOX Series X run FSR 4 faster than the Radeon RX 6700 XT?

A. XBOX Series X benefits from console-specific FSR 4 optimization, specialized INT8 hardware support, and higher memory bandwidth, which lets it process FSR 4 more efficiently.

Q. How much faster is FSR 4 on XBOX Series X compared with the RX 6700 XT?

A. Microsoft reports 3.86ms per frame on XBOX Series X, compared with approximately 5ms on the Radeon RX 6700 XT during Digital Foundry's testing.

Q. Does XBOX Series S support FSR 4?

A. Yes. XBOX Series S supports FSR 4, with processing times ranging from approximately 1.9-2.9ms at 1080p, depending on whether developers use the full or Light model.

Q. Will FSR 4 increase GTA 6's frame rate on XBOX Series X?

A. Not necessarily. Since GTA 6 targets 30fps on consoles, FSR 4 could primarily improve image sharpness and visual quality rather than increase the frame rate.