Equation 4 · Part 1 · An Optical Fabric Turns Off-Package Memory Into an Extension of the Die
Symbol P
What this part means
the power, in watts, that a system actually draws to sustain that bandwidth, attributable specifically to the memory-and-fabric subsystem rather than the whole machine.
Its job in the formula
P is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol P→Article meaning
Where the article explains it
Here BW is realized, measured random-access bandwidth in bytes per second — not a marketing peak, not a sequential-streaming figure, since random access is what most large-model inference and any pooled-memory workload actually demands — and P is the power, in watts, that a system actually draws to sustain that bandwidth, attributable specifically to the memory-and-fabric subsystem rather than the whole machine.
The passage around this formula
…measured random-access bandwidth in bytes per second — not a marketing peak, not a sequential-streaming figure, since random access is what most large-model inference and any pooled-memory workload actually demands — and P is the power, in watts, that a system actually draws to sustain that bandwidth, attributable specifically to the memory-and-fabric subsystem rather than the whole machine. An index above 1 means the optical, unified case delivers more usable bandwidth per unit of energy than wiring the same total…
Learn the underlying idea
A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.
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