SkewAdam: Rethinking MoE Optimizer Memory
SkewAdam drastically cuts MoE training memory by tailoring optimizer state to parameter populations, achieving superior perplexity and enabling training on accessible hardware.

Visual TL;DR
AdamW requires 50.6 GB for moments, dwarfing 12.6 GB bfloat16 weights
From the article 3 mentionsThe memory overhead of optimizers, particularly for large Mixture-of-Experts (MoE) models, presents a significant bottleneck.
From the article 3 mentionsThe memory overhead of optimizers, particularly for large Mixture-of-Experts (MoE) models, presents a significant bottleneck.
recognizes distinct parameter populations within MoE models for tailored state management
From the article 6 mentionsThe SkewAdam optimizer tackles this challenge by recognizing that the distinct parameter populations within MoE models, dense backbone, experts, and router, exhibit differing size and gradient statistics.
tailored state management for backbone, experts, and router based on gradient statistics
From the articleInstead of a uniform approach, SkewAdam applies tailored state management: float32 momentum with a factored second moment for the backbone (5% of parameters), a factored second moment alone for the experts (95%), and an exact second moment for the router (The benefits of SkewAdam extend beyond memory efficiency.
drastically cuts MoE training memory by tailoring optimizer state to parameter populations
From the articleIn a controlled comparison over 82 million tokens, SkewAdam achieved a validation perplexity of 108.4, outperforming AdamW (126.8), Muon (120.2), and Lion (393.7).
enables training on accessible hardware, expanding research and development
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Written by
Daniel SingerEditor, StartupHub.ai
Daniel Singer is the editor of StartupHub.ai, a technology expert and thought leader on AI and its applications across sectors, from fintech and healthcare to developer tooling and consumer software. He writes and tests the tools covered here thoroughly and regularly, and built StartupHub.ai to give founders, operators and buyers a clearer read on what they are actually being sold.
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