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Equation 17 · Part 4 · AI Memory Systems and the Bandwidth Wall in 2035: Scenarios, Signals, and Falsifiable Predictions

subscript

Hkv⋅dhH_{\mathrm{kv}} \cdot d_h
subscript

What this part means

The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.

Its job in the formula

A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.

The passage around this formula

Peer-reviewed evidence, three different levers. DeepSeek-V2 replaces full multi-head keys and values with a low-rank latent projection — reducing HkvH_{\mathrm{kv}} ⋅\cdot dhd_h to a much smaller compressed dimension — and reports a 93.3 percent reduction in KV-cache size relative to the company’s own prior 67-billion-parameter dense model, while extending supported context to 128,000 tokens [ 15 ] . That shrinks the per-token cost of the equation above. StreamingLLM instead shrinks effective S : it keeps only a small window of recent tokens plus a handful of initial “attention sink” tokens, and reports enabling stable generation over sequences up to four million tokens with up to a 22.2-times…

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

Open the illustrated subscripts: which member of a family? guide →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.