Pre-training Distillation for Large Language Models: A Design Space
  Exploration
Authors: name: Hao Peng; name: Xin Lv; name: Yushi Bai; name: Zijun Yao; name: Jiajie Zhang; name: Lei Hou; name: Juanzi Li
Published: 2024-10-21 17:16:13

Abstract: Knowledge distillation (KD) aims to transfer knowledge from a large teacher
model to a smaller student model. Previous work applying KD in the field of
large language models (LLMs) typically focused on the post-training phase,
where the student LLM learns directly from instructions and corresponding
responses generated by the teacher model. In this paper, we extend KD to the
pre-training phase of LLMs, named pre-training distillation (PD). We first
conduct a preliminary experiment using GLM-4-9B as the teacher LLM to distill a
1.9B parameter student LLM, validating the effectiveness of PD. Considering the
key impact factors of distillation, we systematically explore the design space
of pre-training distillation across four aspects: logits processing, loss
selection, scaling law, and offline or online logits. We conduct extensive
experiments to explore the design space of pre-training distillation and find
better configurations and interesting conclusions, such as larger student LLMs
generally benefiting more from pre-training distillation, while a larger
teacher LLM does not necessarily guarantee better results. We hope our
exploration of the design space will inform future practices in pre-training
distillation.