Tuesday, September 22nd 2026
AMD Shows Off Ray Tracing Tech That Slashes GPU Memory Use By 47x
AMD has detailed a new ray tracing technique called tetrahedral cages, and according to a blog post on the company's GPUOpen developer site, it can cut BVH memory use by roughly 47x while speeding up BVH updates by around 90x. AMD demoed the tech on a large scene with about 25,000 independently animated plants, running at 60+ FPS at 1080p on a Radeon RX 9070 XT. In a conventional setup, every uniquely animated object needs its own acceleration structure updated every frame, which gets expensive fast in dense scenes. AMD says the same demo would normally require up to 80 GB of GPU memory and over 300 ms per frame for BVH updates using standard methods. With tetrahedral cages, that dropped to about 1.7 GB of memory and roughly 3.3 ms per frame.
The trick is that instead of animating the dense mesh directly, AMD wraps it in a much simpler deformable cage. The dense geometry and its BVH stay static and reusable, and only the cage itself needs to be animated each frame, so update cost scales with the cage's complexity rather than the triangle count. The tradeoff is losing per-vertex animation control, which is why AMD is positioning it for grass, foliage, and other dense but not individually detailed objects. AMD says the technique can be combined with Microsoft's DirectX ray tracing too. Still, this is only a research showcase in its current state, and there's no word yet on when or if it might show up in games.
Source:
GPUOpen (AMD)
The trick is that instead of animating the dense mesh directly, AMD wraps it in a much simpler deformable cage. The dense geometry and its BVH stay static and reusable, and only the cage itself needs to be animated each frame, so update cost scales with the cage's complexity rather than the triangle count. The tradeoff is losing per-vertex animation control, which is why AMD is positioning it for grass, foliage, and other dense but not individually detailed objects. AMD says the technique can be combined with Microsoft's DirectX ray tracing too. Still, this is only a research showcase in its current state, and there's no word yet on when or if it might show up in games.
31 Comments on AMD Shows Off Ray Tracing Tech That Slashes GPU Memory Use By 47x
Plenty of older games already looked great without RT. Current games, such as BF6, run and look great on a plethora of hardware configs without an RT implementation whatsoever.
In my opinion, pushing RT towards an industry-wide adoption always had more to do with programmed obsolescence and forcing people to upgrade their old hardware, which used to run things all too well.
Now pushing 17.28 times the pixels, with more color depth, perfect anisotropic filtering, antialiasing so that essentially no one complains about jaggies anymore, and at the highest textures and multiple lighting passes and options per frame… it’s better and I notice it.
www.techpowerup.com/download/futuremark-3dmark03/
As for the tech, its interesting how they rethought up the way to reduce the performance hit RT/PT comes with. The demo is just that, a proof of concept demo showing their idea and model works, I'm sure they hope developers will integrate it so they reduce the overhead, also so they can use it on console hardware. I wonder what the first game to use it will be. RT is getting close to realistic, still to shiny/plastic looking in most games for the huge performance hit it costs.
But fundamentally, the tech is good. Having real time realistic lightning and reflections, instead of pre-rendered lightning and fake reflections is a good thing to have, especially if you are a developer.
The first and second generation of RTX cards, ironically, can not play those ray-tracing titles that they have been promoted by nvidia to be used for. I also have to ask, what is with physx? why is nobody using that anymore?
Scaling it, a Gforce 5050 with 8GB of memory or a 9050 with 8GB of memory would be able to run current RT games without issue, im sure future iterations will allow for PT capabilities.
From the published research:So, not for gaming. Unless you want Flickervision.
d1qx31qr3h6wln.cloudfront.net/publications/MicroMesh_generation.pdf
Hardware support was included in Ada, therefore it’s able to run in realtime while remaining watertight, unlike AMD’s version which has to do a software fallback and cannot run in realtime on their current hardware.
Yes, features matter.
Edit: To head off the usual four of you before you go off on your rants, Nvidia’s work is cited in the AMD presentation.
Furthermore, the software version of PhysX for CPUs was intentionally crippled and acted more like a demo slideshow designed to drive users to buy a high-end Nvidia card, rather than serving as a genuine option. This is another practice Nvidia has implemented a few times over at least the last 15 years. This changed much later, somewhere around 2014 I believe, when hardware PhysX was already dead and Nvidia removed the locks from its drivers.
Nowadays, Nvidia drivers no longer disable PhysX and CUDA when an AMD or Intel primary graphics card is present; instead, they activate and function normally whenever an Nvidia graphics card is added to the system, even as a second GPU. Of course, by the time Nvidia decided to make this move, hardware PhysX was already dead—which is precisely why they did it. If hardware PhysX were still alive, it would still be locked down.The typical story we've been seeing for 20 years. Someone has an idea (2023), Nvidia grabs it and builds a proprietary version exclusively for its hardware (2024), AMD steps in and proposes an open version that works everywhere (2026). We should thank both of them, Nvidia and AMD. Without Nvidia, many technologies wouldn't exist. Without AMD, many technologies would remain exclusive to Nvidia hardware, and rendering a game on non-Nvidia hardware would result in a much worse visual presentation on screen. We saw these exact shenanigans back with PhysX, and it was a disgrace.
For goodness shake can you stop for a single thread going in your usual tangent. We get it, it's the worst company on the planet.
You do not need to have Ray-Tracing to have shadows.