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Published equation contexts

p−1m+p−1\frac{p-1}{m+p-1}

Why this formula appears here

Pipeline parallelism splits the model by depth, giving each device a contiguous run of layers. The traffic is point-to-point rather than collective — activations forward, gradients backward, between neighbouring stages only — and the volume is modest. Its cost is not bandwidth but idleness. GPipe’s contribution was to split each batch into micro-batches so that stages could work concurrently instead of waiting for a whole batch to traverse the pipeline [ 6 ] . With p stages and m micro-batches, the standard accounting gives a bubble fraction of p−1m+p−1\frac{p-1}{m+p-1}. which says the only cure for pipeline idleness is more micro-batches in flight, and micro-batches cost memory. Narayanan and…

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pp

Symbol p

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

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mm

Symbol m

m occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.

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How to interpret it

With a fixed numerator, increasing a nonzero denominator reduces the fraction.

Research cited beside this formula

Published contexts (1)

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p−1m+p−1,\frac{p-1}{m+p-1},

Equation 3 · AI Hardware & Semiconductors

The Network Is the Computer Again

This mathematical expression combines the displayed quantities; its precise role follows from the surrounding article text.

Pipeline parallelism splits the model by depth, giving each device a contiguous run of layers. The traffic is point-to-point rather than collective — activations forward, gradients backward, between neighbouring stages only — and the volume is modest. Its cost is not bandwidth but idleness. GPipe’s contribution was to split each batch into micro-batches so that stages could work concurrently instead of waiting for a whole batch to traverse the pipeline [ 6 ] . With p stages and m micro-batches, the standard accounting gives a bubble fraction of p−1m+p−1\frac{p-1}{m+p-1}. which says the only cure for pipeline idleness is more micro-batches in flight, and micro-batches cost memory. Narayanan and…

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