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Equation 13 · Part 2 · The Physical Plant: Power, Cooling, and Networks in an AI Datacenter

subscript

EITE_{\mathrm{IT}}
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

Three failure modes follow directly from the algebra, and they are analysis rather than sourced claim. One: moving a cooling function inside the IT boundary improves PUE. Server fans are counted in EITE_{\mathrm{IT}} ; a room that pushes 15% of rack power through fans reports a better PUE than one that removes the same heat with facility pumps, while consuming more total energy for the same computation. Two: PUE is a ratio, so it improves when the denominator grows. A hall running its accelerators flat out reports a better PUE than the same hall running at half load, with no efficiency change whatever. Three: PUE says nothing about work done. A facility computing nothing at full power can…

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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 article section

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