What is voltage droop?

Voltage droop is the impact on the power delivery network (PDN) as sudden changes in demand overwhelm the capability of the PDN network; these dramatic changes are quite common in the AI world when algorithms or models are changed rapidly and the entire accelerator array goes active, or when doing rapid power management state transition changes. This can lead to severe performance degradation, limit energy efficiency, and even catastrophic timing failures.

Why Does it Matter?

While voltage droop is not a new term, it is not completely understood because of the lack of visibility into what exactly is happening with the power grid, so the impact is that people typically overprovision their grids and become less competitive because of the large guardbands they’re deploying.
Beyond catastrophic failures, voltage droop can result in missed performance targets or silent data corruption (SDCs). It’s a critical concern in the tech industry, with teams across the industry exploring its effects at SoC, system, and system-of-systems levels.