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UpLoop trains looped Transformers by upcycling, matching a dense baseline's parameter count, tokens and FLOPs

AspireAI community · arXiv (cs.LG, cs.CL)
Looped language models improve reasoning by running the same weights more than once, but each extra pass costs training FLOPs. UpLoop is a pretraining schedule that reaches that capability without extra compute: it starts from a shallow Transformer, progressively grows depth by copying learned layers, and spends the compute saved early on repeated execution of a shared middle block later in training. The authors report matching a standard dense baseline exactly in final parameter count, total training tokens and training FLOPs, with the average score across 22 downstream tasks rising from 22.99 to 27.52 at 1.3B parameters, and gains extending to mathematical reasoning after supervised fine-tuning. The comparison is at the 1.3B scale, so whether the same trade holds for frontier-size models is untested.
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