Quick answer: Epic's Unreal Engine 5.8.4 hotfix adds ASDTool, which builds the shader database stores use for Microsoft's Advanced Shader Delivery. It covers Windows D3D12 SM6 builds, doesn't support ray tracing PSOs, works alongside PSO precaching, and Epic Games Store support is planned for early 2027.
Unreal Engine 5.8 now supports Microsoft's Advanced Shader Delivery (ASD), the system that downloads precompiled shaders with a game instead of making your PC compile them at first launch or mid-game. Epic's 5.8.4 hotfix, posted on the Unreal Engine forums on October 20, lists a new ASDTool that generates State Object Databases (SODBs) for compute shaders and bundled PSOs from a cooked game, plus tools for testing compilation and registration locally. Epic has also published documentation on the workflow.
An SODB is a GPU-independent file with a game's shaders and PSOs, made from a cooked Windows build and submitted to the store. The store compiles it into Precompiled Shader Databases (PSDBs) for each GPU family and driver, then downloads the matching one to the player's PC. ASDTool is a standalone command-line program that doesn't need the editor or a running game, but developers have to build it from engine source.
There are limits. Per Epic's documentation, ASD only applies to Windows D3D12 Shader Model 6 builds, ray tracing PSOs aren't supported, and it works alongside PSO precaching and bundled PSO caches rather than replacing them. Any PSO missing from the database still compiles at runtime, so it won't remove every hitch. Games also don't get it automatically: developers have to create the database and the store has to support it. Epic lists the Microsoft Store today, with Epic Games Store support planned for early 2027.
Microsoft's October 21 DirectX blog post, which also expanded ASD to NVIDIA RTX, AMD, Intel and Qualcomm GPUs on Windows 11, says Unreal Engine 5.8.4 developers can build SODBs into their process now and that Unity support is coming in 2027. Microsoft also highlighted ASD in its October 15 Windows 11 update.