NAVIGATION

What is an Attention Sink?

Definition

Attention Sink

An Attention Sink is a phenomenon where autoregressive LLMs focus a massive amount of attention weights on the first few tokens of a sequence, regardless of their semantic meaning. Keeping these tokens in the cache prevents performance collapse in long conversations.

Why It Matters for AI Builders

Key to managing sequence memory and token weights during infinite context window streaming, persistent chatbot hosting, and memory cache tuning; optimizing Attention Sink prevents attention processing bottlenecks and keeps execution latencies low.

Detailed Deep Dive

Attention Sinks refer to the phenomenon in autoregressive language models where the first few tokens in a sequence receive disproportionately high attention scores, acting as a mathematical dumping ground for softmax normalization. By preserving these initial tokens in the key-value cache, developers can implement sliding-window context caches that enable infinite sequence generation without crash.

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Frequently Asked Questions

Q:Why do attention sinks occur?

Because the Softmax function requires attention weights to sum to 1, and the initial tokens act as a "dumping ground" for unnecessary attention.

Q:How is this phenomenon used in streaming LLMs?

By keeping the first few tokens (the sink) permanently cached along with a sliding window of recent tokens, allowing infinite generation without retraining.

Quick Facts

  • CategoryNeural Architectures
  • Key ApplicationInfinite context window streaming, persistent chatbot hosting, and memory cache tuning

Coverage Trend12 Weeks

12w agoToday

Cite This Term

Reference this definition in your articles, research, or documentation to credit this source:

[Attention Sink | SPIDITS Glossary](https://spidits.com/ai-glossary/attention-sink)

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