AMD And Sony Disclose Project Amethyst Details For PS6 Path Tracing
In a video posted to the official PlayStation YouTube channel this morning, AMD and Sony detailed a few major advancements in AMD's GPU architecture developed under the two companies' Project Amethyst collaboration—advancements that point toward strong path tracing performance on both PlayStation 6 and AMD's upcoming RDNA 5 architecture. While PlayStation 5 Pro and extant RDNA 4 GPUs both boast substantial advancements in hybrid rasterized and ray-tracing workloads, path tracing—a form of ray tracing that does not rely on rasterization for primary visualization, seen in projects like Portal With RTX and Quake 2 RTX—has long been a pain point on AMD hardware, and still notoriously demanding on performance with Intel and even NVIDIA GPU hardware.
As lead PlayStation architect Mark Cerny explains with the help of AMD SVP and GM of its Computing and Graphics Group, Jack Huynh, the next generation of AMD GPU dies, including those in the PlayStation 6, will be built with Neural Arrays of Compute Units, all loaded with new Radiance Cores. While GPUs are already stacked with plenty of Compute Units and thousands of GPU cores split across them, the issue with this approach (particularly in the context of ray-tracing) is that those tasks still have to be subdivided across those cores and CUs properly, which can be inefficient for tasks not easily solved by the GPU. According to AMD and Sony, Neural Arrays allow for more seamless communication between components on a GPU die, allowing them to "work together like a single AI engine" with "bigger ML models and more efficiency".
Another problem with modern ray tracing solutions is how CPU-bound ray traversal calculations are while still being so demanding on the GPU—an issue being targeted by Radiance Cores to "free up the CPU for geometry and simulation" and allow GPU cores to focus on shading and lighting. The result, says Jack Huynh, is a "cleaner, faster and more efficient pipeline built for the next generation of ray traced visuals." Mark Cerny confirms, stating "there's a significant speed boost that comes from putting the traversal logic in hardware, and a further boost that comes from that hardware operating independently from the shader cores."
Memory bandwidth is another huge limitation for ray-tracing performance; this is exactly why NVIDIA took the expensive leap to GDDR7 memory in its latest GPUs. As Jack Huynh explains, "Current GPU memory bandwidth limitations hinder the seamless adoption of next-gen rendering techniques, requiring significantly more bandwidth for 4K+ textures and ray tracing denoising maps for smooth asset streaming." Project Amethyst has also improved upon AMD's Delta Color Compression (DCC) to help overcome these GPU bandwidth issues. DCC was introduced with AMD's GCN 1.2 architecture that debuted with the Radeon R9 285 (codenamed Tonga) back in 2014, so it's not new technology, but now, AMD will be upgrading it to "Universal Compression" to realize even greater memory bandwidth efficiency.
As discussed in our previous coverage of Project Amethyst, these advancements are being made to benefit AMD hardware as a whole, not exclusively PlayStation hardware. So this news bodes well for PC gamers as well, especially those hoping for more performant ray tracing solutions on AMD graphics cards.
While we'll be waiting to see benchmarks and trailers to confirm the full breadth of improvements really being made here, it would appear that Project Amethyst is proving to be a very productive collaboration between AMD and Sony's PlayStation division. The news that the PlayStation 6 will actually be capable of path tracing and that graphics on par with what we see in Cyberpunk 2077's path traced RT Overdrive modes may actually be possible on consoles in just a few years time is truly exciting. It could even be a sign that RDNA 5 may see AMD making an unqualified shot at the GPU performance crown for the first time since ray tracing was introduced—and that bodes well for all gamers, not just PlayStation fans.
Image Credit: AMD, Sony
