PC Gamer's headline is accurate, but it needs the context Microsoft attached to it. Here is what the update actually does, why the demo numbers are so extreme, and when (if ever) it reaches your games.
What Microsoft announced
Microsoft describes the update as the biggest change to DirectX Raytracing since the API arrived in 2018. It has two main parts, both in preview in the DirectX 12 Agility SDK 1.722 with Shader Model 6.10:
- Clustered Geometry: instead of rebuilding whole acceleration structures when objects move or change, models are split into small reusable clusters of up to 256 triangles (and 256 vertices) that get built once and reused. This attacks the bottom-level acceleration structure (BLAS) bottleneck.
- Partitioned TLAS (PTLAS): the same idea applied to the whole scene — ray tracing can focus on the region that changed while keeping acceleration-structure data elsewhere, instead of rebuilding everything.
- GPU-driven acceleration structure builds round out the package.
The demo numbers, exactly as Microsoft gave them
On a Radeon RX 9070 test scene using conventional rebuilds, the scene ran at 1.2 fps. Switching to Clustered Geometry took it to 79 fps — about 66 times faster. Per-frame build time fell from 788 ms to 3.11 ms. Total acceleration-structure memory fell from 7,519 MiB to 774 MiB, about 90% less. Ray-tracing execution time fell from 72.6 ms to 9.27 ms in the same comparison.
There is a cost Microsoft did not hide: clustered builds need far more temporary scratch memory — up from 1.8 MB to 526 MB in the demo — so developers have to plan around that. And the 90% figure is ray-tracing structure memory only, not a game's total VRAM use. A game using 12 GB of VRAM will not suddenly use 1.2 GB.
Why the demo is so extreme
The test scene is a stress case designed to punish conventional rebuilds: extremely detailed, heavily animated geometry where old-style acceleration structures must be rebuilt constantly. Real games vary enormously in how much they rebuild per frame, which is why Microsoft warned in unusually blunt terms that games should not expect anything close to these gains. Think of 90% as the ceiling in a worst case for the old method, not a promise.
Which GPUs are supported
No new dedicated ray-tracing hardware is required. Microsoft lists support across Nvidia GeForce RTX cards (from the RTX 20 series up, per coverage of the announcement), AMD Radeon RX 9000 series, Intel Arc B-series GPUs, Intel Core Ultra processors, and Qualcomm Snapdragon SoCs, subject to drivers. Nvidia already offers a similar approach through RTX Mega Geometry, so this is partly Microsoft bringing the same idea to the whole DirectX ecosystem.
When will games use it?
Not soon. Everything is still in preview, requires Windows Developer Mode to switch on, and needs compatible drivers. Games built around Clustered Geometry and PTLAS are some way off, and Microsoft has not announced when the update reaches retail status. Treat this as a developer preview of where ray tracing is heading — cheaper, more detailed ray-traced scenes on existing hardware — not as a patch that will speed up the games you own today.
Frequently asked questions
Will DirectX Clustered Geometry cut my games' VRAM by 90%?
No. The ~90% figure is for ray-tracing acceleration-structure memory in Microsoft's stress-test scene (7,519 MiB down to 774 MiB), not total game VRAM. Real gains in shipping games will be much smaller, and Microsoft says so itself.
What is Clustered Geometry?
A DirectX Raytracing technique that splits models into small reusable clusters (up to 256 triangles each) instead of rebuilding whole acceleration structures, cutting build time and memory for animated, detailed scenes.
Which graphics cards support it?
It needs no new hardware: Nvidia RTX cards, AMD RX 9000 series, Intel Arc B-series, Intel Core Ultra, and Snapdragon SoCs are listed, subject to drivers — but the features are preview-only and need Windows Developer Mode for now.
When will games support Clustered Geometry?
Microsoft has not announced a retail date. The features are in the DirectX 12 Agility SDK 1.722 preview, so games using them are still some way off.
Sources: Microsoft's DirectX developer blog (Clustered Geometry and Partitioned TLAS, DirectX 12 Agility SDK 1.722 preview), and coverage by TechSpot, VideoCardz, and PC Gamer of the RX 9070 demo figures.
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