Streaming, Fast and Slow: Cognitive Load-Aware Streaming for Efficient LLM Serving

Abstract: Generative conversational interfaces powered by LLMs typically stream output token-by-token at a rate determined by computational budget, often neglecting actual human reading speeds and the cognitive load associated with the content. This mismatch frequently leads to inefficient use of computational resources. For example, in cloud-based services, streaming content faster than users can read appears unnecessary, resulting in wasted computational resources and potential delays for other users, particularly during peak usage periods. To address this issue, we propose an adaptive streaming method that dynamically adjusts the pacing of LLM streaming output in real-time based on inferred cognitive load. Our approach estimates the cognitive load associated with streaming content and strategically slows down the stream during complex or information-rich segments, thereby freeing computational resources for other users. Our statistical analysis of computational savings, combined with crowdsourced user studies, provides insights into the trade-offs between service efficiency and user satisfaction, demonstrating that our method can significantly reduce computational consumption up to 16.8\%. This context-aware computational resource management strategy presents a practical framework for enhancing system efficiency in cloud-based conversational AI interfaces without compromising user experience.