DirectX preview could cut ray tracing memory use by up to 90%

Microsoft is previewing two new DirectX Raytracing features, called Clustered Geometry and Partitioned TLAS, that change how the data behind ray tracing is stored and updated. In its own testing, the company says they could cut ray tracing memory load by as much as 90%, and it describes the update as the most significant to DXR since the API debuted in 2018. ¹

Start with what is physically different. Ray tracing already works against simplified stand-ins for the detailed models you see on screen, because re-checking full-detail geometry every frame would take too long. Clustered Geometry slices the detailed models into packages of 256 triangles or fewer.

The payoff is in the updating. Rather than searching the entire map each frame for what changed, the renderer only touches the regions it knows are different. That shrinks the amount of ray tracing data your machine has to check and refresh frame to frame. ¹

Now the numbers. On an AMD Radeon RX 9070, Microsoft’s test showed memory use falling from 7.5 GB to 774 MB, and frame rates rising from 1.2 fps to 79 fps. ¹ The approach is similar in spirit to Nvidia’s RTX Mega Geometry, but this is a DirectX feature rather than a vendor-specific one, so it is not tied to a team green GPU. ¹

I always ask what the test setup was when I see “up to” figures, and here the answer matters. Microsoft says its specialised test environment will not be replicated by every game. ¹ There is also a cost: working with all those small triangle clusters uses noticeably more temporary scratch memory than traditional methods, which creates logistical work for developers. ¹

Availability is the other open question. The update is not widely available yet, and there is no word on when players will be able to use it. Developers can try the experimental features today with matching Agility SDK preview headers and runtime, a supporting driver, and Windows Developer Mode. ¹

Our read: The 7.5 GB to 774 MB result is a best case from a controlled test, and I would treat it as a ceiling, not a promise. Still, this is the kind of unglamorous engineering win I like: the same hardware doing the same job with far less memory. If real games land anywhere near even half of that saving, cards with limited VRAM could keep ray tracing on for longer. What would change my mind is developer feedback on that extra scratch memory, and any sign that shipping games see only small gains. We will know more once this leaves preview.

On the bench: nothing to install or buy today, since this is a developer preview. But if you are weighing a GPU upgrade while memory and card prices are high, it is worth knowing that software like this may stretch what you already own, once games support it.

Footnotes

1. PC Gamer, “Ray tracing memory usage could be reduced by up to 90% thanks to ‘most significant’ DirectX update”. Retrieved November 2, 2026. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷