Adaptive Head Budgeting for Efficient Multi-Head Attention

Abstract:Multi-head attention enables Transformers to capture diverse representations, but all attention heads are typically activated for every input, regardless of task complexity. For coarse-grained tasks such as text classification, where relevant information is often global, this fixed allocation can introduce unnecessary computation. We propose BudgetFormer, a Transformer architecture that dynamically allocates attention heads on a per-input basis. The model learns both a head budget and a relevance distribution to select the most informative heads. To support effective head selection, we introduce a training strategy that balances exploration and exploitation. Experiments on text classification tasks show that BudgetFormer reduces FLOPs and memory usage while matching or surpassing the performance of standard multi-head attention. These results highlight adaptive head allocation as an effective approach to improving Transformer efficiency and performance.

Machine Learning (cs.LG)

arXiv:2604.22583 [cs.LG]

(or arXiv:2604.22583v2 [cs.LG] for this version)

https://doi.org/10.48550/arXiv.2604.22583 Focus to learn more arXiv-issued DOI via DataCite

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