MoE Parallel Folding: Heterogeneous Parallelism Mappings for Efficient Large-Scale MoE Model Training with Megatron Core

Fuente: arXiv
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Main Authors: Liu, Dennis, Yan, Zijie, Yao, Xin, Liu, Tong, Korthikanti, Vijay, Wu, Evan, Fan, Shiqing, Deng, Gao, Bai, Hongxiao, Chang, Jianbin, Aithal, Ashwath, Andersch, Michael, Shoeybi, Mohammad, Yao, Jiajie, Zhou, Chandler, Wu, David, Li, Xipeng, Yang, June
Format: Preprint
Published: 2025
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author Liu, Dennis
Yan, Zijie
Yao, Xin
Liu, Tong
Korthikanti, Vijay
Wu, Evan
Fan, Shiqing
Deng, Gao
Bai, Hongxiao
Chang, Jianbin
Aithal, Ashwath
Andersch, Michael
Shoeybi, Mohammad
Yao, Jiajie
Zhou, Chandler
Wu, David
Li, Xipeng
Yang, June
author_facet Liu, Dennis
Yan, Zijie
Yao, Xin
Liu, Tong
Korthikanti, Vijay
Wu, Evan
Fan, Shiqing
Deng, Gao
Bai, Hongxiao
Chang, Jianbin
Aithal, Ashwath
Andersch, Michael
Shoeybi, Mohammad
Yao, Jiajie
Zhou, Chandler
Wu, David
Li, Xipeng
Yang, June
contents Mixture of Experts (MoE) models enhance neural network scalability by dynamically selecting relevant experts per input token, enabling larger model sizes while maintaining manageable computation costs. However, efficient training of large-scale MoE models across thousands of GPUs presents significant challenges due to limitations in existing parallelism strategies. We introduce an end-to-end training framework for large-scale MoE models that utilizes five-dimensional hybrid parallelism: Tensor Parallelism, Expert Parallelism, Context Parallelism, Data Parallelism, and Pipeline Parallelism. Central to our approach is MoE Parallel Folding, a novel strategy that decouples the parallelization of attention and MoE layers in Transformer models, allowing each layer type to adopt optimal parallel configurations. Additionally, we develop a flexible token-level dispatcher that supports both token-dropping and token-dropless MoE training across all five dimensions of parallelism. This dispatcher accommodates dynamic tensor shapes and coordinates different parallelism schemes for Attention and MoE layers, facilitating complex parallelism implementations. Our experiments demonstrate significant improvements in training efficiency and scalability. We achieve up to 49.3% Model Flops Utilization (MFU) for the Mixtral 8x22B model and 39.0% MFU for the Qwen2-57B-A14B model on H100 GPUs, outperforming existing methods. The framework scales efficiently up to 1,024 GPUs and maintains high performance with sequence lengths up to 128K tokens, validating its effectiveness for large-scale MoE model training. The code is available in Megatron-Core.
format Preprint
id arxiv_https___arxiv_org_abs_2504_14960
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle MoE Parallel Folding: Heterogeneous Parallelism Mappings for Efficient Large-Scale MoE Model Training with Megatron Core
Liu, Dennis
Yan, Zijie
Yao, Xin
Liu, Tong
Korthikanti, Vijay
Wu, Evan
Fan, Shiqing
Deng, Gao
Bai, Hongxiao
Chang, Jianbin
Aithal, Ashwath
Andersch, Michael
Shoeybi, Mohammad
Yao, Jiajie
Zhou, Chandler
Wu, David
Li, Xipeng
Yang, June
Machine Learning
Distributed, Parallel, and Cluster Computing
Mixture of Experts (MoE) models enhance neural network scalability by dynamically selecting relevant experts per input token, enabling larger model sizes while maintaining manageable computation costs. However, efficient training of large-scale MoE models across thousands of GPUs presents significant challenges due to limitations in existing parallelism strategies. We introduce an end-to-end training framework for large-scale MoE models that utilizes five-dimensional hybrid parallelism: Tensor Parallelism, Expert Parallelism, Context Parallelism, Data Parallelism, and Pipeline Parallelism. Central to our approach is MoE Parallel Folding, a novel strategy that decouples the parallelization of attention and MoE layers in Transformer models, allowing each layer type to adopt optimal parallel configurations. Additionally, we develop a flexible token-level dispatcher that supports both token-dropping and token-dropless MoE training across all five dimensions of parallelism. This dispatcher accommodates dynamic tensor shapes and coordinates different parallelism schemes for Attention and MoE layers, facilitating complex parallelism implementations. Our experiments demonstrate significant improvements in training efficiency and scalability. We achieve up to 49.3% Model Flops Utilization (MFU) for the Mixtral 8x22B model and 39.0% MFU for the Qwen2-57B-A14B model on H100 GPUs, outperforming existing methods. The framework scales efficiently up to 1,024 GPUs and maintains high performance with sequence lengths up to 128K tokens, validating its effectiveness for large-scale MoE model training. The code is available in Megatron-Core.
title MoE Parallel Folding: Heterogeneous Parallelism Mappings for Efficient Large-Scale MoE Model Training with Megatron Core
topic Machine Learning
Distributed, Parallel, and Cluster Computing
url https://arxiv.org/abs/2504.14960