FoMoE: Breaking the Full-Replica Barrier with a Federation of MoEs
On the map: Mixture-of-experts → Efficient MoE training and inference systems
Abstract (arXiv)
Pre-training Large Language Models (LLMs) typically demands large-scale infrastructure with tightly coupled hardware accelerators. Mixture-of-Experts (MoEs) architectures partially decouple model capacity from per-token compute. This efficiency alone does not make MoE training feasible over ordinary Internet links or loosely connected commodity hardware since active expert routing still assumes high-speed datacenter fabrics. Low-communication methods such as DiLoCo and Photon reduce synchronization frequency across distributed sites, mitigating bandwidth constraints, yet still require full model replicas at every site. This creates a mismatch: modern MoEs have sparse data paths, but their distributed training infrastructure remains communication-dense and memory-inefficient, limiting attempts to pool geographically distributed compute. In this work, we introduce FoMoE, a system that breaks the full-replica paradigm by partitioning expert layers across workers and skipping non-resident experts during local training. We demonstrate that FoMoE: (I) reduces communication costs by up to 1.42x over efficient baselines and 45.44x over Distributed Data Parallelism (DDP) via partial expert replication in controlled regimes; (II) achieves empirical throughput speedups of up to 1.4x through the skip-token mechanism; and (III) shows stable routing in the trained regimes and projects the communication/memory benefits to 100B-scale configurations through system modeling.
Key facts. No citing papers in the map yet (data through 14 Oct 2026). Placed in Efficient MoE training and inference systems, one of 12 directions in Mixture-of-experts. Builds on 50 of its 70 references that are in the map. First posted on arXiv 17 Jun 2026.
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50 of 70 references.
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- 2022MegaBlocks: Efficient Sparse Training with Mixture-of-Experts29 Nov
- 2022Tutel: Adaptive Mixture-of-Experts at Scale7 Jun
- 2020Towards Crowdsourced Training of Large Neural Networks using Decentralized Mixture-of-Experts10 Feb
Other references · 47
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