Sony reveals that its new PSSR upscaling for the Playstation 5 Pro has the same 'core' as AMD's FSR Redstone but that doesn't necessarily mean older AMD PC graphics cards are set to get an FSR upgrade

Sony PlayStation lead system architect Mark Cerny has done an in-depth interview with Digital Foundry. The full discussion isn't out yet, but a few very interesting tidbits have been released regarding Sony's latest PSSR upscaling technology for the PlayStation 5 Pro, the related Project Amethyst collaboration with AMD, and how that all ties in with FSR upscaling on the PC.

Indeed, one of the pressing unknowns that Digital Foundry wanted to clear up was the relationship between Sony's newly upgraded PSSR upscaling and FSR Redstone, the latter being the latest machine learning-based build of AMD's upscaling tech for the PC.

"Just to clarify a few things about the collaboration with AMD, the new PSSR uses the same core co-developed algorithm as FSR Redstone's upscaling," Cerny told Digital Foundry. Cery also said that the PlayStation platform could consequently get frame generation in future.

"FSR Frame Generation is also based on co-developed technology (or as my good friend Jack Huynh puts it, 'co-engineered technology'). I’m very happy with how that work is progressing, and an equivalent frame generation library should be seen at some point on PlayStation platforms," he said.

But for the PC, the interesting bit is how the PS5 Pro handles AI-based upscaling. "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," Cerny clarifies.

"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 seem to make too much difference in results; as both SIE and AMD have just released their refreshed models, it will be an excellent test of how closely we can match our systems."

The context here, of course, is that the PS5 Pro uses AMD graphics hardware. Typically, it's described as being a hybrid between RDNA 2 and RDNA 3, but with some RDNA 4-derived ray-tracing capabilities and some additional custom machine-learning capabilities on top.

But as Cerny himself emphasises, when it comes to upscaling and particularly running ML-based upscaling, the PS5 Pro has a different matrix math implementation to RDNA 4, hence the need to run INT8 as opposed to FP8 for PSSR 2.

Of course, anyone who has been following the whole FSR 4 / FSR Redstone saga closely will recall that AMD leaked an unofficial version of FSR 4, which included an INT8 codepath. That has allowed a community effort to provide support for FSR 4 for older RDNA 2 and RDNA 3 AMD graphics cards via the Optiscaler tool, the latest version of which now supports RDNA 2 without the need to run ancient drivers.

Immediately, that begs the question of the relationship between Sony's INT8 PSSR 2 and the unofficial INT8 version of FSR 4 that leaked out and can be run on older AMD PC graphics cards.

Now, one assumption that's tempting to make is that whatever Sony and AMD have cooked up to run on the PS5 Pro would be a good candidate for an INT8 ML-based upscaler for older AMD PC. GPUs. Heck, maybe that leaked INT8 version of FSR 4 only exists because Sony and AMD have been working on INT8 ML upscaling for the PlayStation?

Sadly, none of that may really follow. As Nick explained back when the PS5 Pro's technical details leaked, it has some significantly upgraded INT8 hardware support compared to older RDNA generations. That means the PS5 Pro is rated at 300 TOPS for INT8 performance compared to a mere 75 TOPS for the Radeon RX 7800 XT. Even the Radeon RX 7900 XTX is only rated at 123 TOPS by AMD.

Long story short, there's a huge gulf in INT8 performance between the PS5 Pro and pre-RDNA 4 AMD PC GPU generations. So, it does not seem at all safe to assume that anything Sony and AMD cook up to run on the PS5 Pro in terms of upscaling is a good candidate for those older PC graphics cards, sadly.

That's a pity, because Digital Foundry has also done a detailed analysis of the latest upgraded version of PSSR with machine learning and found it to be dramatically improved from the original PSSR, the latter not using any machine-learning technology and being based on spatial and temporal algorithms.

Still, hope remains that AMD might eventually deliver an official release of some version of FSR 4 or FSR Redstone for owners of older RDNA GPUs. Optiscaler shows it can work pretty well, and with all the billions AMD is making from its server CPUs and AI chips right now, it doesn't seem like a huge ask.