Microsoft DirectX 12 update slashes ray tracing VRAM usage by 90%

Microsoft released the Agility SDK 1.722 preview for DirectX 12 on October 28, 2026, calling it the most significant update to DirectX Raytracing (DXR) since 2018. It adds clustered geometry, partitioned TLAS (PTLAS), and a GPU-driven API for building acceleration structures, aimed at cutting the cost of ray tracing complex, changing scenes.

How Clustered Geometry and Partitioned TLAS work

Animation, streaming, and generated geometry can force games to rebuild large bottom-level acceleration structures again and again. Clustered Geometry breaks that work into small, reusable clusters of up to 256 triangles and 256 vertices, which can be recombined instead of rebuilt from scratch. Partitioned TLAS tackles the scene-wide top-level structure. It focuses updates on the regions that changed and keeps the data elsewhere, so the cost scales with the amount of change rather than the size of the whole world.

What Microsoft’s AMD test shows

Microsoft ran its Clustered Geometry sample on an AMD Radeon RX 9070. Against a traditional bottom-level rebuild, frame rate rose from 1.2 FPS to 79 FPS, and per-frame GPU build time fell from 788 ms to 3.11 ms. Total acceleration structure memory, including the top-level structure, dropped from 7,519 MiB to 774 MiB, a reduction of 89.7%. In a separate domino sample, PTLAS cut the top-level update from 2.88 ms to 0.79 ms per frame, although ray traversal got slightly slower.

Why games will not see the same gains

Microsoft calls the scene a test playground and warns developers not to assume games will see wins of this size. Clustered Geometry also needs far more scratch memory while building, with static build scratch rising from 1.83 MiB to 526 MiB in the sample, and the technique does not support refits.

Hardware support and availability

The features need no new hardware beyond existing ray tracing support, but they are not ready for players yet. Developers need the 1.722 preview runtime, the Shader Model 6.10 preview shader compiler, a supporting driver, and Windows Developer Mode. Supported hardware currently covers all Nvidia RTX GPUs, AMD Radeon RX 9000 series cards, Intel Arc B-series graphics, and Intel Core Ultra 200V and Series 3 processors. Qualcomm is targeting driver support for Snapdragon X2 in the first half of 2027, while support for some older ray tracing GPUs is still to be determined. Microsoft has not announced a retail release date.