Asked about Attention, conceptually

Why is long context expensive?

An answer that works

Attention compares every position with every other, so cost grows with the square of sequence length. Doubling the input quadruples the work, which is why context limits exist and why efficient attention is an active research area.

Reading an answer is not being able to give one. The section that teaches this is Attention, conceptually, 8 hours of Transformers & attention.

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