Equation 4 · Part 1 · Serving a Frontier Model: The KV Cache, Batching, and What a Token Actually Costs

Symbol d_head

d_{\mathrm{head}}

d_{\mathrm{head}}

What this part means

the head dimension.

Its job in the formula

$d_h$ ead is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Full expressionSymbol d_headArticle meaning

Where the article explains it

for L layers, $n_{\mathrm{kv}}$ key–value heads, head dimension $d_{\mathrm{head}}$ , sequence length s , batch size b , and p bytes per element.

The passage around this formula

for L layers, $n_{\mathrm{kv}}$ key–value heads, head dimension $d_{\mathrm{head}}$ , sequence length s , batch size b , and p bytes per element. The factor of two counts keys and values.

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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.

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Sources cited in the article section

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