Overview
Field: LLM training Authors: Shreyas Subramanian, Adewale Akinfaderin, Akarsha Sehwag Published: 2025-07-12 arXiv: 2507.08699
Summary
Recent work identified Super Weights, individual parameters whose removal degrades model performance by orders of magnitude. This paper shows that this degradation does not universally apply to all LLMs, and—more importantly—that the importance of these weights does not make them viable fine-tuning targets.
Key findings
- Training Super Weights in isolation (100 to 8,192 parameters) drops accuracy to random-guessing levels on both OLMo-1B and OLMo-7B.
- The failure is specific to Super Weight coordinates: training an equal number of randomly chosen positions in the same
down_projlayers instead improves over the baseline. - Vanilla LoRA, which updates every position in attention weight matrices through low-rank structure, succeeds using only 0.16% of parameters.
Conclusion
These findings establish that parameter importance does not imply parameter trainability in isolation. Effective fine-tuning relies on structured decomposition across entire layers rather than targeting individually critical weights, even ones as influential as Super Weights.
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Paper: arXiv:2507.08699