Reducing Peak Memory Usage for Modern Multimodal Large Language Model Pipelines

Junwan Kim, Hyunkyung Bae


Abstract
Multimodal large language models (MLLMs) have recently demonstrated strong capabilities in understanding and generating responses from diverse visual inputs, including high-resolution images and long video sequences. As these models scale to richer visual representations, inference increasingly relies on storing large numbers of vision tokens in the key–value (KV) cache, making memory consumption a central bottleneck. Existing methods address this issue by identifying redundancy in vision tokens and compressing the cache, but such compression is typically applied only after all inputs are processed, resulting in high peak memory usage during the prefill stage. In this work, we show that MLLMs exhibit inherent structural regularities and representational redundancy that can be exploited to control memory growth throughout inference. Based on this insight, we propose a sequential input-compression mechanism that enforces a fixed memory budget by performing structure-aware key–value cache compression during the prefill process. This approach substantially reduces peak memory usage while maintaining generative performance with only minimal degradation, enabling more practical and memory-efficient multimodal inference.
Anthology ID:
2026.findings-acl.1422
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
28518–28526
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URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.findings-acl.1422/
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Bibkey:
Cite (ACL):
Junwan Kim and Hyunkyung Bae. 2026. Reducing Peak Memory Usage for Modern Multimodal Large Language Model Pipelines. In Findings of the Association for Computational Linguistics: ACL 2026, pages 28518–28526, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Reducing Peak Memory Usage for Modern Multimodal Large Language Model Pipelines (Kim & Bae, Findings 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.findings-acl.1422.pdf
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