arXiv Machine Learning

Compute-Optimal Pretrain--Fine-tune in Ridge Gradient Descent

The paper studies how to allocate a fixed computational budget between pretraining and fine‑tuning in a two‑stage ridge regression setting. By modeling the process as a compute‑split problem and analyzing data‑dependent evaluation geometries, it derives the optimal split in terms of prediction‑relevant spectral components of the pretraining and fine‑tuning empirical covariances. The analysis uses a basis‑invariant eigenspace decomposition and perturbative control of non‑commuting dynamics to capture how pretraining directions influence downstream predictions.

arXiv AI
Jul 7

OmniOpt: Taxonomy, Geometry, and Benchmarking of Modern Optimizers

arXiv:2607. 04033v1 Announce Type: cross Abstract: Optimizer selection for large-scale model training has become a system-level design decision constrained jointly by compute, memory, tuning budget, and task diversity, yet the landscape of over one hundred methods remains fragmented.

By Siyuan Li, Jiabao Pan, Yumou Liu, Zhuoli Ouyang, Xin Jin, Xinglong Xu, Jingxuan Wei, Shengye Pang, Jintao Che, Xuanhe Zhou, Conghui He, Cheng Tan
arXiv AI
Sep 3

TaRA: Training-Aware Low-Rank Adaptation Initialization

TaRA: Training-Aware Low-Rank Adaptation Initialization proposes a new way to initialize LoRA by aligning the gradients of low‑rank factors with those of the full‑rank weight matrix. This approach directly incorporates training dynamics, improving gradient fidelity at the start of fine‑tuning while adding negligible computational cost. Experiments on a variety of challenging fine‑tuning tasks show that TaRA consistently outperforms existing state‑of‑the‑art initialization methods, offering a simple, robust, and scalable solution for effective LoRA initialization.

By Taehyeon Kim, Eunhyeok Park