Learn about Shader Execution Reordering (SER), a performance optimization that unlocks the potential for better ray and memory coherency in ray tracing shaders.
Overview
NVIDIA's Shader Execution Reordering (SER) is a new feature aimed at optimizing shader performance and improving in-game frame rates, particularly in ray tracing applications. By mitigating shading divergence through thread reordering, SER enhances ray and memory coherency, leading to more efficient shading operations.
What You'll Learn
1
How to integrate Shader Execution Reordering in your ray tracing applications
2
Why reducing shading divergence is crucial for performance in ray tracing
3
When to apply SER for optimal performance in Unreal Engine 5
Prerequisites & Requirements
- Understanding of ray tracing and shader programming concepts
- Access to a GPU that supports DXR 1.0 or higher and the appropriate NVIDIA drivers
- Familiarity with HLSL and the NVIDIA API(optional)
Key Questions Answered
What is Shader Execution Reordering and how does it improve performance?
Shader Execution Reordering (SER) is a performance optimization feature that reorders threads on the GPU to reduce shading divergence. By improving ray and memory coherency, SER enhances shading efficiency, leading to better frame rates in ray tracing applications.
How can developers integrate SER using the NVIDIA API?
Developers can integrate SER by initializing NVAPI, checking for SER support, and setting up a fake UAV slot in the global root signature. This allows the use of SER functions in shader code to optimize ray tracing operations.
What are the benefits of SER in Unreal Engine 5?
SER provides significant performance gains in ray tracing operations within Unreal Engine 5, with up to 40% increased speeds on 40 series cards. It enhances offline path tracing and improves Lumen performance when hardware ray tracing is enabled.
What specific performance improvements can be achieved with SER?
With SER, developers can achieve performance improvements ranging from 20-50% in path tracing and around 20-30% in Lumen reflections. These gains stem from reduced shading divergence and more efficient execution of ray tracing calculations.
Key Statistics & Figures
Performance increase in ray tracing operations
up to 40%
Observed on 40 series cards when using SER in Unreal Engine 5.
Performance improvement in path tracing
20-50%
Achieved by applying SER to reduce divergence in material evaluations.
Performance savings in Lumen reflections
20-30%
Realized through the integration of SER in the Lumen system.
Technologies & Tools
API
Nvidia API
Used to integrate Shader Execution Reordering features in ray tracing applications.
Game Engine
Unreal Engine 5
Utilizes SER for performance optimization in ray tracing operations.
Key Actionable Insights
1Implement Shader Execution Reordering in your ray tracing projects to enhance performance.By integrating SER, developers can significantly reduce shading divergence, leading to smoother frame rates and improved rendering efficiency in complex scenes.
2Utilize the NVIDIA API to access SER features effectively.Familiarizing yourself with the NVIDIA API and its extensions will allow you to leverage SER optimally, especially in high-performance applications like Unreal Engine 5.
3Optimize shader code by selectively applying SER where it has the most impact.Focus on areas in your shader code that exhibit high divergence, such as material evaluations in path tracing, to maximize the benefits of SER.
Common Pitfalls
1
Failing to check for SER support before implementation can lead to runtime errors.
Always verify that the GPU and driver support SER to avoid issues during shader execution.
2
Overcomplicating shader code when integrating SER may negate performance benefits.
Keep shader modifications focused and efficient to ensure that the intended performance improvements are realized.
Related Concepts
Ray Tracing
Shader Programming
Performance Optimization Techniques