Minibatch persistency, eight years later: what batch reuse costs in steps and joules, and what it saves in data

Minibatch persistency reuses data instead of reading it: rather than drawing a fresh minibatch at every optimizer step, it takes K consecutive steps on the same one. Absorbed into data echoing in 2019, it has carried one objection -- that reuse merely imitates a larger learning rate -- and no baseli