Plenty of news regarding GPUs and the tech behind them has come out of GDC 2025, and Microsoft has now announced an update to DirectX Raytracing (DXR) at its DirectX State of the Union presentation.
Microsoft Principal Program Manager Cassie Hoef posted more information about the DirectX Raytracing 1.2 update in Microsoft’s Dev Blogs, stating:
“This update promises groundbreaking performance improvements and breathtaking visual fidelity, marking another milestone in our mission to deliver immersive, realistic experiences to gamers everywhere.”
The update will affect Microsoft’s partners like NVIDIA, AMD, Intel, and Qualcomm, who rely on Microsoft’s tools to implement the latest tech into their hardware and games.
Also shared by Microsoft is more information regarding cooperative vectors and neural rendering, which I wrote about following the GDC Advanced Graphics Summit hosted earlier this week.
DirectX Raytracing (DXR) — What is it?
DirectX Raytracing (DXR) is an add-on for DirectX 12 that was introduced by Microsoft at the same GDC conference in 2018.
The API is what allows modern GPUs to power ray tracing via DirectX without getting in the way of standard rasterization, with performance being shared between the two methods.
The new DXR 1.2 is set to add “game-changing performance boosts” on the backs of two new technologies.
Here’s how Microsoft explains them:
- Opacity micromaps significantly optimize alpha-tested geometry, delivering up to 2.3x performance improvement in path-traced games. By efficiently managing opacity data, OMM reduces shader invocations and greatly enhances rendering efficiency without compromising visual quality.
- Shader execution reordering offers a major leap forward in rendering performance — up to 2x faster in some scenarios — by intelligently grouping shader execution to enhance GPU efficiency, reduce divergence, and boost frame rates, making raytraced titles smoother and more immersive than ever. This feature paves the way for more path-traced games in the future.
The standout number here is the 2.3x performance jump in path-traced games using DXR 1.2 opacity micromaps.
Path tracing is a more intensive and complex version of ray tracing, and it understandably requires a lot more power from your GPU even compared to normal ray tracing. This level of performance boost isn’t minor.
The other big performance jump is the “up to 2x faster” rendering performance thanks to shader execution reordering.
Not only does it improve efficiency and boost frame rates, it’s also expected — according to Microsoft — to raise the appeal of path tracing in games due to the reduced performance costs.
Microsoft says NVIDIA is already on board with driver support for its RTX GPUs (going back to RTX 20-series), while it’s still working with AMD, Intel, and Qualcomm “to ensure widespread adoption.”
DXR 1.2 also comes to PIX on day one
PIX is a DirectX 12 tool used by game developers to debug and tune performance. It’s set to receive DXR 1.2 support from day one.
Microsoft outlines a number of new tools for PIX:
- PIX API Preview: A brand-new API giving developers programmatic access to PIX functionality and data via a D3D12-like API, available in C++, C# and Python. A private preview is coming in April 2025.
- Custom Visualizers: Building on announcements over the past year, we announced new functionality to give unprecedented customization while viewing buffers, meshes, and textures inside the PIX UI.
- PIX UX Refresh: A modernized, more intuitive, and more discoverable user experience is coming to PIX in April 2025! The many improvements include a new Visual Studio-like layout editor system, unlocking more PIX UI customization than ever before.
Microsoft shares key uses for neural rendering
It’s no secret that Microsoft has been working with NVIDIA to bring neural rendering and cooperative vectors to DirectX.
More information was shared at GDC 2025 earlier in the week, this specific quote coming from Direct3D development manager Shawn Hargreaves:
“Microsoft is adding cooperative vector support to DirectX and HLSL, starting with a preview this April. This will advance the future of graphics programming by enabling neural rendering across the gaming industry. Unlocking Tensor Cores on NVIDIA RTX will allow developers to fully leverage RTX Neural Shaders for richer, more immersive experiences on Windows.”
Microsoft showed off how these technologies will directly affect game development and play:
- Neural Block Texture Compression is a new graphics technique that dramatically reduces memory usage, while maintaining exceptional visual fidelity. Overall, our partners at Intel shared that by leveraging cooperative vectors to power advanced neural compression models, they saw a 10x speed up in inference performance.
- Real-time path tracing can be enhanced by neural supersampling and denoising, combining two of the most cutting-edge graphics innovations to provide realistic visuals at practical performance levels.
So, how long do developers have to wait to get their hands on DXR 1.2?
Not long at all. Microsoft says the full package with DXR 1.2, PIX updates, and cooperative vectors is coming to a preview Agility SDK toward the end of April.
