An update to Microsoft DirectX makes ray tracing a lot easier
Microsoft is always working on DirectX behind the scenes, making big and small tweaks to the API. With its latest update, which brings the DirectX Agility SDK up to version 1.619, there are some interesting improvements to the ray tracing functionality.
I’m talking specifically about Shader Execution Reordering (SER), a feature that officially arrived in DirectX Raytracing (DXR) 1.2. It’s been in preview mode since it was announced last year at GDC 2025. The big news? Microsoft is seeing up to a 90% frame rate increase with SER enabled in early demos.
Why is Shader Execution Reordering (SER) in DirectX a big deal?
As Microsoft explains in its DirectX SER blog post, one of the best things about ray tracing comes from something called diffraction.
Dissociation usually occurs when rays are unexpectedly shot into the scene. Shooting rays at an object in the scene makes your game look more realistic, but at the same time, it can cause the GPU to lose compatibility. The GPU is forced to process these rays sequentially rather than parallel. It’s inefficient, and puts more load on the hardware.
Adding more ray tracing cores will not fix the problem because the process happens at the shader level. SER solves this problem by allowing shaders to group rays into coherent clusters, allowing the GPU to deal with them in parallel.
SER works alongside something called Opacity Micromaps (OMMs), another feature that allows the GPU to skip unnecessary blurring when a ray bounces off an alpha-scanned object. As you might guess, this together reduces the load on the GPU, which in turn improves general performance.
Just how much operating profit can you expect? Microsoft gives us a few examples of its internal testing using some demos that you can check out for yourself via the GitHub repo. With SER enabled on the NVIDIA RTX 4090 GPU, tests show a 40% framerate increase compared to not using SER at all.
Most impressive is that Microsoft claims to have seen “several configurations of Intel Arc B-Series GPUs” achieve a massive 90% frame rate improvement with SER enabled.
Windows Central takes Shader Execution Reordering (SER)
The huge performance gains Microsoft has given are probably not indicative of what you’d expect from real-world gaming. Still, making SER a standard feature in DirectX will make it much easier for developers to use it, and that’s a win for everyone.
Given how demanding routing can be, SER can be one of the keys to unlocking great graphics on most GPUs that can’t run without the feature. The best part? You don’t need a new GPU.
I want to know what you think!
What are your thoughts on Microsoft adding SER to its latest DirectX release? Do you think the real world performance will be much lower compared to the demos? Which GPUs do you think would benefit the most? Let me know in the comments section!
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