In the Hugging Face accelerate library, the distinction between the number of machines and the number of processes dictates how a training workload is distributed. The number of machines refers to the distinct physical or virtual servers involved in the computation. The number of processes, on the other hand, specifies how many worker instances are launched on each machine. For instance, if you have two machines and specify four processes, two processes will run on each machine. This allows for flexible configurations, ranging from single-machine multi-process execution to large-scale distributed training across numerous machines.
Properly configuring these settings is crucial for maximizing hardware utilization and training efficiency. Distributing the workload across multiple processes within a single machine leverages multiple CPU cores or GPUs, enabling parallel processing. Extending this across multiple machines allows for scaling beyond the resources of a single device, accelerating large model training. Historically, distributing deep learning training required complex setups and significant coding effort. The accelerate library simplifies this process, abstracting away much of the underlying complexity and allowing researchers and developers to focus on model development rather than infrastructure management.
