Rounding in Preconditioner Space: Redesigning 4-bit AdamW Optimizer-State Quantization
Presents novel quantization techniques for reducing memory footprint in large-scale model training while maintaining optimization performance.
AI Summary
Researchers redesign 4-bit AdamW optimizer-state with ZIP-SR and ZE-EDEN methods, reducing validation-loss gap to 32-bit AdamW by up to 70% in GPT- and Llama-style models.
Excerpt
Quantizing AdamW's optimizer states reduces persistent storage, but quantization errors propagate through the moment recurrences and perturb subsequent adaptive updates. We redesign 4-bit optimizer-state quantization for AdamW from the perspective of \emph{rounding space}: the coordinate in which a quantizer chooses between adjacent reconstruction levels. For the second moment, a local analysis of the quantization cell adjacent to zero shows that small mean state error need not imply small mean
