What problem does it solve?
Managing and executing large-scale LLM pretraining workflows is complex and error-prone due to multi-dimensional parallelism, memory constraints, checkpoint interoperability, and performance tuning for modern accelerators. This Skill consolidates best-practice configurations and operational guidance to reliably pretrain models from 8 to 512+ GPUs while maximizing throughput and fault tolerance.
Core Features & Use Cases
- Composable 4D parallelism: Guides for FSDP2, tensor parallelism, pipeline parallelism, and context parallelism to scale models across nodes and GPUs.
- Performance optimizations: Float8 integration, torch.compile usage, activation checkpointing, and microbench-informed filtering to boost H100 throughput.
- Checkpointing & interoperability: Distributed Checkpoint (DCP) patterns, async checkpointing, and conversion paths to/from HuggingFace formats for recovery and fine-tuning.
- Use Cases: Single-node 8-GPU pretraining of Llama 3.1 8B, multi-node SLURM jobs for 70B+ models, and large-scale 4D parallel pretraining for 405B+ models with seed checkpoints for pipeline parallelism.
Quick Start
Launch a pretraining run by creating or editing your TOML config for the target model and running the run_train.sh entrypoint with that config file.