MSA: Memory Sparse Attention for Efficient End-to-End Memory Model Scaling to 100M Tokens

TL;DR

MSA introduces a scalable, end-to-end trainable memory model with linear complexity, enabling efficient processing of up to 100 million tokens for long-term memory tasks in AI.

Contribution

The paper presents Memory Sparse Attention (MSA), a novel framework that achieves scalable, stable, and efficient long-context modeling surpassing existing methods.

Findings

MSA maintains less than 9% degradation from 16K to 100M tokens.

MSA enables 100M-token inference on 2xA800 GPUs.

MSA outperforms state-of-the-art LLMs and memory systems in long-context benchmarks.

Abstract

Long-term memory is a cornerstone of human intelligence. Enabling AI to process lifetime-scale information remains a long-standing pursuit in the field. Due to the constraints of full-attention architectures, the effective context length of large language models (LLMs) is typically limited to 1M tokens. Existing approaches, such as hybrid linear attention, fixed-size memory states (e.g., RNNs), and external storage methods like RAG or agent systems, attempt to extend this limit. However, they often suffer from severe precision degradation and rapidly increasing latency as context length grows, an inability to dynamically modify memory content, or a lack of end-to-end optimization. These bottlenecks impede complex scenarios like large-corpus summarization, Digital Twins, and long-history agent reasoning, while limiting memory capacity and slowing inference. We present Memory Sparse Attention (MSA), an end-to-end trainable, efficient, and massively scalable memory model framework. Through core innovations including scalable sparse attention and document-wise RoPE, MSA achieves linear complexity in both training and inference while maintaining exceptional stability, exhibiting less than 9% degradation when scaling from 16K to 100M tokens. Furthermore, KV cache compression, combined with Memory Parallel, enables 100M-token inference on 2xA800 GPUs. We also propose Memory Interleaving to facilitate complex multi-hop reasoning across scattered memory segments. MSA significantly surpasses frontier LLMs, state-of-the-art RAG systems, and leading memory agents in long-context benchmarks. These results demonstrate that by decoupling memory capacity from reasoning, MSA provides a scalable foundation to endow general-purpose models with intrinsic, lifetime-scale memory.