New PS5 Pro details explain what "advanced ray tracing" really means

A new video featuring Mark Cerny has been released
He provides some interesting insight into the PS5 Pro's tech
This includes a breakdown of its ray tracing features

A new technical seminar featuring PlayStation 5 Pro lead console architect Mark Cerny has been posted to the official PlayStation YouTube channel. It provides some interesting new insights into the hardware that powers the PS5 Pro, including an explanation of what “advanced ray tracing” actually means.

The video is quite technical and begins with Cerny outlining what Sony is hoping to achieve with the PS5 Pro. He says that each new generation of consoles targets “broad improvements” and “significant new capabilities” that allow for a “tremendous step up in what the player experiences”. Mid-generation refreshes like the PS5 Pro, in contrast, are much more “tightly focused” and generally hone in on a few key areas like the GPU.

When developing the PS5 Pro, Cerny states that the focus was to create minimal extra work for developers while still offering games that play “noticeably better”.

Cerny also details some of the technical improvements in the PS5 Pro. While not entirely new information, it does provide a useful recap.

He explains that the 16GB of GGDR6 RAM found in the console is 28% faster than PS5, with over 1GB more memory available to games in order to help with PSSR, ray tracing, and increased rendering resolution. The PS5 Pro also features 2GB of slower DDR5 RAM for the operating system.

He goes on to address some common misconceptions, specifically regarding the power of the PS5 Pro’s GPU. He states that the GPU runs at 16.7 TFLOPs, debunking an earlier myth that it actually ran at a massive 33.5 TFLOPs. He reaffirms the claim that, overall, developers can expect to achieve a 45% increase in rendering speed which he calls “a huge improvement.”

We also get some insight into what the PS5 Pro’s advanced ray tracing entails in technical terms. He states that one of the “top priorities” of PS5 Pro development was “finding ways to accelerate” the computation of ray tracing. This was achieved through a combination of GPU improvements combined and new RDNA features in collaboration with AMD.

He estimates that calculation of rays now occurs at roughly “double or triple the speed of PS5”. He also explains a new acceleration structure and stack management in hardware. Put simply, the new acceleration structure interprets data regarding simulated geometry in order to work out where rays hit objects via an intersection engine. Objects are divided into “boxes”, which make it easier for the engine to work out which ones will be affected by rays.

Every time a box is intersected by a ray, it reduces in size to narrow down exactly what needs to be simulated. Compared to the PS5, the PS5 Pro encodes boxes in larger groups with an intersection engine that is twice as fast - massively increasing ray tracing performance.

The stack management in hardware then addresses the issue of divergence - which occurs when certain pixels being processed require different actions to others, generally increasing the time needed to render them. This impacts ray tracing performance, as there are lots of possible ways for a ray to be interpreted when it comes to curved or bumpy surfaces.

While the base PS5 uses a complex stack management system to accommodate for this, on PS5 Pro, stack management is in the console’s hardware - simplifying the process which “further increases the speed of execution”. This, in addition to a few other changes, leads to significantly more consistent ray tracing performance, helping games look and run better.

Although I certainly wouldn't recommend it to more casual players, you can check out the rest of the technical seminar for even more information.