Sony's updated PSSR is a version of FSR 4 INT8 that could run on RDNA 2 and RDNA 3 GPUs

Digital Foundry has posted an interview with PlayStation console architect Mark Cerny about the recent release of the updated version of PSSR (PlayStation Spectral Super Resolution) for the PlayStation 5 Pro. The update, also referred to as PSSR 2, delivers a notable improvement in image quality, with results comparable to AMD's FSR 4.1.

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In the interview, Mark Cerny confirms in more detail that PSSR and FSR Redstone share the same technology base. One of the more notable takeaways is how PSSR works compared to FSR 4.1 and how it leverages the PS5 Pro's less capable AI hardware to deliver a similar result.

"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," Mark Cerny explains. "The MAC counts (i.e., the amount of math involved) also vary a bit, and training data is similar but not exactly the same. None of the above factors seems to make much difference in the results. The various flavors in the updated FSR Upscaling really are rather close to the new PSSR."

In addition to confirming that PSSR is tailored specifically to the PS5 Pro, its hardware, and how it's used to achieve a 4K output, the fact that it's INT8 compared to FSR 4's FP8 does add weight to the idea that a version of FSR 4 could be released that runs on older RDNA 2 and RDNA 3 Radeon graphics cards. This is something we know for a fact because AMD has previously, and inadvertently, released the FSR 4 source code, which included a work-in-progress INT8 version.

This FSR 4 INT8 model, which does not match the image quality and performance of FSR 4 running on a Radeon RX 9000 Series GPU, has already been used to get FSR 4 working on older Radeon GPUs with results that offer better overall image quality than FSR 2 and FSR 3. Interestingly, you could assume from this interview that the leaked FSR 4 INT8 version was an early version of the new PSSR and was never intended for deployment on PC.

With AI-powered upscaling being the game-changer it is on both PC and console, a version of FSR 4 for RDNA 2 and RDNA 3 hardware, like the upcoming Steam Machine, would be a big win for AMD in the eyes of PC gamers everywhere.