AI inference glossary
ParallelismDP

Data parallelism

In plain English

Data parallelism makes multiple copies of the model and divides incoming work among them, like opening more identical checkout lanes.

Technical definition

Data parallelism runs replicated model or layer groups on multiple ranks and distributes requests or tokens among those replicas.

Engineering details

Classic DP duplicates the complete model. In LLM serving, hybrid forms such as data-parallel attention can replicate attention while expert weights use a different sharding strategy. Each replica handles separate work with less per-layer synchronization than TP.

Why it matters

DP scales aggregate capacity cleanly when weights fit, but replication consumes memory and repeats weight reads. Load balancing and cache locality determine how evenly the replicas are used.

How to read it in InferenceX

Modern MoE deployments combine DP, TP, and EP. Read the DP count together with the other two dimensions.