AI inference glossary
Software

CUDA graphs

Also known as graph capture, full-graph mode

In plain English

CUDA graphs record a whole sequence of chip operations once and replay it as a unit, removing the per-step cost of launching each one.

Technical definition

CUDA graph capture records a sequence of kernel launches and their dependencies into a replayable graph, so the sequence is submitted once rather than launched operation by operation.

Engineering details

A decode step issues many small kernels, and at small batch sizes the launch and scheduling overhead between them can rival the arithmetic. Capturing the step removes that per-launch cost. The catch is that a graph is fixed: shapes must be stable, so engines capture per bucket and leave genuinely dynamic work outside the graph.

Why it matters

This is a latency optimization more than a throughput one, and it matters most exactly where batches are small and interactivity is high. It also interacts with everything that changes shape, which is why variable-length agentic traffic can defeat a runtime that specializes too eagerly and recompiles for nearly every request it sees.

How to read it in InferenceX

Graph usage is part of the engine image a recipe pins, so it can move a curve with no change in hardware. Recipes may capture stable producers while leaving request-dependent attention eager, which is a deliberate compromise between capture coverage and shape flexibility.