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Training & Fine-tuningHard· Communication Bottlenecks· AllReduce· Distributed Training

At what point does the AllReduce become the bottleneck,...

The bottleneck is defined by the compute-to-communication ratio. When the communication overhead of AllReduce dominates the compute time, the system is communication-bound. Remedies include lossy gradient compression, which may hurt convergence; asynchronous SGD, which introduces staleness; or utilizing ZeRO Stage 2, which interleaves communication with computation layer by layer to hide latency.

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