PlayStation 5's PSSR 2.0 uses AMD's FSR 4's INT8 version that may skip PC RDNA 2 & 3 GPUs

AMD made a major misstep in recent days by leaking the entire FSR 4 libraries and source code to its GitHub repository via the AMD OpenGPU Project. While the company subsequently took it offline, modders had already taken notice.

That’s because the files contained information about an INT8 version of FSR 4, a lighter build that could run on older RDNA 2 and RDNA 3 GPUs; as of now, AMD has no intention of releasing FSR 4 for older Radeon cards. What’s even more surprising is that the PS5 and PS5 Pro, based on RDNA 2, are running an INT8 version of FSR 4, which Sony calls its “upgraded PSSR” upscaling solution.

Modders Have Already Pulled and Patched FSR 4’s INT8 Build for Radeon RX 6000 and 7000 Series Graphics Cards

For context, when AMD first unveiled FSR 4, or FSR Redstone, the company made it clear that it’s specifically designed for its latest RDNA 4 GPUs in the Radeon RX 9000 series. Now, it’s evident from the GitHub repository leak that the lighter INT8 iteration of FSR 4 could run effectively on RDNA 2 and RDNA 3 GPUs, barring RX 6000 and RX 7000 series users from the technology.

However, this didn’t stop modders, who pulled the libraries from the repository before AMD took them down and began patching their games to bring the INT8 FSR 4 build to RX 6000 and RX 7000 series GPUs.

PlayStation 5’s Upgraded PSSR, or PSSR 2.0, Is Running the INT8 Version of FSR 4

Sony received and rolled out the upgraded version of PSSR, which many are calling PSSR 2.0, in Resident Evil: Requiem. In a recent interview, PlayStation lead system architect Mark Cerny sat down with Digital Foundry and explained how the new PSSR tech ties back to AMD.

Mark Cerny discussed the technical differences between FSR 4 and the new PSSR. He said, “FSR Redstone and the new PSSR have somewhat different implementations due to the underlying hardware, e.g., FSR Upscaling uses 8-bit floating point, and PSSR uses 8-bit integer.”

He further explained that the core technology remains the same, but the training process differs to suit each platform, i.e., PC and PlayStation 5. He continued:

“In practice, the same model is used, but it’s trained on different data, e.g., if targeting a 2:1 fixed upscale, then the training data used is just for that upsampling ratio, and that different training results in different parameters… Not seeing too much difference in the results, the various flavors in the updated FSR Upscaling really are rather close to the new PSSR.”

This is pretty much confirmation that PSSR 2.0 on the PS5 Pro is effectively running the INT8 version of FSR 4 that AMD leaked in its GitHub libraries. To make matters worse, AMD has remained silent on the matter, and it seems that Team Red won’t be bringing FSR 4 to older Radeon GPUs, making buying a RX 9000 series GPU possibly the only surefire way to get official FSR 4 support from Team Red.

Buy the ASRock Radeon RX 9070 XT Challenger 16GB OC on Amazon