arXiv AI By Shenghui Li, Thiemo voigt

LoRA on a Budget: Function-Aware Post-Hoc Compression for Adapter Fleets

Read the original on arXiv AI →

The paper introduces Functional Rank Allocation (FRA), a method for post‑hoc compression of LoRA adapters that balances rank allocation across layers and adapters within a shared budget. FRA constructs functional rank‑distortion frontiers for each adapter, uses dynamic programming to search for low‑risk truncations, and then applies minimax allocation to optimize overall fleet performance. Experiments on 78 adapters from three public fleets show that FRA outperforms uniform spectral compression, especially in constrained‑budget scenarios.

Machine-generated by The Flow from the publisher's headline and feed description — not written or checked by a human. The full article lives at arXiv AI.

arXiv Machine Learning
Sep 14

Rank-Efficient LoRA via Joint Tangent-Space Optimization under Isotropic Curvature

The paper introduces ISO-LoRA, an optimizer that improves rank utilization in Low‑Rank Adaptation (LoRA) by coupling factor updates through spectral descent on the induced tangent perturbation in weight space. Experiments on GPT‑2 adaptation show that standard optimizers like AdamW concentrate updates in a few singular directions, whereas ISO-LoRA distributes energy more evenly, leading to higher effective rank and better downstream performance across 0.1B‑7B models. The authors provide theoretical guarantees under a stylized spiked‑gradient model and demonstrate that ISO-LoRA consistently outperforms factor‑wise optimizers, especially at moderate‑to‑large LoRA ranks.

By Zihan Zhu, Zhehang Du, Xuyang Chen, Tim Tsz-Kit Lau, Jiayuan Wu, X. Y. Han, Qi Long, Weijie Su
arXiv AI
Oct 2

FedLore: Communication and Memory Efficient Federated Learning via Shared Gradient Low-Rank Projection

FedLore introduces a communication- and memory-efficient federated learning framework that shares a low-rank optimization basis across clients each round, mitigating subspace fragmentation and enabling exact low-rank aggregation. By refreshing this shared basis across rounds, FedLore allows model updates to exceed the per-round rank budget while maintaining a provable $O(T^{-1/2})$ stationarity bound under standard assumptions. Experiments on vision and language tasks, including federated pre‑training, demonstrate that FedLore outperforms low‑rank adapter baselines and matches or surpasses full‑parameter training while reducing communication and optimizer‑state memory.

By Junkang Liu