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Equation 6 · What an AI Accelerator Actually Is: Silicon, Packaging, and the Memory It Can Reach

What does this equation mean?

Igemm=2mnks (mk+kn+mn),I_{\mathrm{gemm}} = \frac{2mnk}{s\,(mk + kn + mn)},

Read the formula alongside the article passage below. Each part has a deeper page with its role in the equation, the supporting passage and nearby citations.

Start with2mnk
Divide bys(mk + kn + mn)
This relates toI_gemm
How to read the two sides of this formula. Follow the article passage for the meaning of each quantity.

This equation states an equality: the expressions on both sides have the same value under the article’s assumptions. Read the equation part by part below; each part has a contextual explanation and a link to its mathematical background.

Read it piece by piece

IgemmI_{\mathrm{gemm}}

Symbol I_gemm

the ratio of work done to bytes moved.

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mm

Symbol m

the number of rows in the first matrix.

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nn

Symbol n

the number of columns in the second matrix.

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kk

Symbol k

the shared inner dimension: columns in the first matrix and rows in the second.

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ss

Symbol s

bytes occupied by each element.

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=

=

The expressions on both sides represent the same quantity under the stated assumptions.

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fraction

fraction

Divide the expression above the line by the one below it.

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addition

addition

Add the term after the plus sign to the term or group before it.

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subscript

subscript

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.

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2mnk2mnk

Numerator: 2mnk

The complete quantity above the fraction bar.

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s (mk+kn+mn)s\,(mk + kn + mn)

Denominator: s(mk + kn + mn)

The complete quantity below the fraction bar; it must be nonzero for this division.

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How to interpret it

With a fixed numerator, increasing a nonzero denominator reduces the fraction. Read it with the definitions, units, and assumptions supplied by the article.

What the article says around this equation

Multiplying an m ×\times k matrix by a k ×\times n matrix performs 2mnk floating-point operations while touching mk + kn + mn elements. If each element occupies s bytes, the ratio of work done to bytes moved is Igemm=2mnks (mk+kn+mn)I_{\mathrm{gemm}} = \frac{2mnk}{s\,(mk + kn + mn)}. which for large square matrices grows in proportion to the dimension. Double the matrix size and you roughly double the work performed per byte fetched. Almost nothing else in general-purpose computing behaves this way, and it is the entire economic basis for building a machine around one operation.

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Sources cited in the article section

These citations give research context. Read each source to check which claims it supports.

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