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…