Microsoft Launches Agility SDK 1.619 with Major DirectX 12 Upgrades
Microsoft has released the Agility SDK 1.619, introducing significant improvements to DirectX 12, including the new Shader Model 6.9 and DirectX Ray Tracing (DXR) 1.2 features. This update brings enhanced graphics capabilities and optimisations aimed at improving performance and efficiency across supported GPUs. The SDK also incorporates a variety of Direct3D (D3D) enhancements requested by developers to better align with modern GPU architectures.
Key Features: Shader Model 6.9 and DXR 1.2
The highlight of this SDK release is Shader Model 6.9, which introduces several new features such as Long Vector support, 16-bit float specials, and mandatory 16-bit and 64-bit shader and wave operations. Long Vector capability allows High-Level Shading Language (HLSL) to handle vectors longer than four elements, scaling up to 1024 elements, enabling more complex and efficient shader computations.
Alongside Shader Model 6.9, the update brings DXR 1.2 enhancements, notably Opacity Micromaps (OMMs) and Shader Execution Reordering (SER). OMMs improve the handling of alpha-tested geometry by offloading costly AnyHit shader invocations to hardware, resulting in significant performance gains. For example, NVIDIA demos show frame rates jumping from 55 FPS to 90 FPS with OMM enabled in ray-traced scenes. SER optimises ray tracing by allowing shaders to reorder execution for better parallelism, reducing rendering times substantially in demanding titles like Remedy’s Alan Wake.
Additional DirectX 12 Improvements
Beyond shader and ray tracing features, Agility SDK 1.619 introduces several Direct3D 12 enhancements. The resource view creation APIs have been revised to allow buffer views to be measured using byte offsets and sizes instead of elements, addressing limitations in previous GPU architectures. This change also improves error handling by returning HRESULT codes instead of void.
Other updates include kernel-level periodic trim notifications, which help applications manage memory residency more effectively without requiring new driver support. The maximum 1D dispatch grid size has been increased to device-specific values, accommodating the needs of modern hardware. Additionally, a new CPU timeline query resolve feature reduces GPU overhead by enabling certain queries to be resolved on the CPU timeline.
Hardware Support Across GPU Vendors
Support for the new SDK features varies among GPU manufacturers. NVIDIA’s entire RTX lineup supports the update, with hardware-accelerated OMMs and SER available on RTX 40 series and newer GPUs. Older NVIDIA hardware supports OMMs via software emulation.
AMD supports the D3D enhancements on RX 7000 and RX 9000 series GPUs, but DXR 1.2 and Shader Model 6.9 features are limited to the RDNA 4 (RX 9000) architecture. Intel’s Arc B-Series GPUs support all features, with some D3D functionalities extending to Lunar Lake CPUs.
Interestingly, while NVIDIA RTX 40+ GPUs and Intel Arc B-Series GPUs support shader execution reordering, AMD’s RX 9000 series supports the API but does not perform reordering. Opacity Micromaps remain exclusive to RTX 40 series and above for hardware acceleration at this time.
Looking Ahead
Microsoft’s Agility SDK 1.619 marks a substantial step forward in DirectX 12 capabilities, particularly for ray tracing and shader performance. With broad hardware support from major GPU vendors, developers can expect to leverage these improvements in upcoming games and applications. Continued driver updates and hardware evolution will likely expand support and performance benefits further.