← All resources

The performance impact of vertex shader exports

Auto-discovered

Blog Advanced

Kostas Anagnostou

Visit resource ↗

Description

The performance impact of vertex shader exports is a September 2025 Interplay of Light blog post by Kostas Anagnostou measuring how many float4 attributes passed from vertex to pixel shaders affect draw cost on NVIDIA hardware.

It reports an experiment with up to ten float4 exports on an RTX 3080 mobile, and uses Nsight GPU Trace to relate costs to ISBE, Primitive Engine, and TRAM allocation and fill stalls. It contrasts unused exports being optimized away on NVIDIA, different AMD GCN behavior, float versus float4 scaling, and mixed float and int packing.

It is for advanced graphics programmers optimizing mesh passes and attribute packing. Comfort with G-buffer style shaders and GPU profilers helps.

The article is a free WordPress post with code snippets, measurement charts, and further reading pointers.

It is useful when draw cost grows with attribute count and you need a hardware-grounded explanation of vertex-to-pixel bottlenecks.