arXiv AI

TensorDex: A Compact, Tensor-Centric Storage System for Modern AI Models

TensorDex is a lossless, tensor‑centric storage system designed to reduce the storage footprint of large language models by performing delta compression at the tensor level. It decomposes models into individual tensors, uses compact fingerprints to predict which tensors can be compressed together, and incrementally clusters tensors to select effective reference bases as new models arrive. In experiments on 2,890 Hugging Face models, TensorDex cuts storage usage by 70.5%, outperforms the previous best system by 37%, and achieves compression and decompression speeds of 22.9 GB/s and 28.4 GB/s, respectively.

arXiv Machine Learning
Sep 25

A JoLT for the KV cache: Near-Lossless KV Cache Compression via Joint Rank-bit Allocation

The paper introduces JoLT, a training‑free compressor that jointly allocates rank and precision for key‑value (KV) cache compression in long‑context language models. JoLT treats grouped prefill caches as fourth‑order tensors, applies partial Tucker decomposition along token and feature modes, and uses a rotated low‑bit quantizer for residuals, all governed by a single Lagrangian dual under a global byte constraint. Across five models from four architecture families, JoLT achieves 2–3× compression with less than 0.2% perplexity loss, and near‑lossless retrieval accuracy on LLaMA‑3.1‑8B at 64K context up to 3× compression.

By Rahul Krishnan, Volker Schulz
arXiv AI
Sep 1

Tensor Methods for Language Models: From Token Representation to Training, Adaptation, Inference, Compression, and Interpretability

This survey reviews tensor methods applied to large language models, framing them through a seven‑stage lifecycle (tokenization, embeddings, pre‑training, adaptation, compression, inference, interpretability) and a component view (embeddings, attention, feed‑forward networks). It offers unified notation, theoretical foundations, and comparative analyses of tensorization strategies for Transformer components, while highlighting evaluation protocol differences and model scale effects. The paper also introduces a new metric, ρ_gap, to quantify the gap between theoretical memory savings and actual system‑level speedup, and connects tensor techniques to related efficiency and probabilistic methods.

By Matvei Tarasov, Salman Ahmadi-Asl, Andre L. F. de Almeida, Andrzej Cichocki
arXiv Machine Learning
Oct 8

NeuralZip: Reusable Setup for Fast Lossless Compression

NeuralZip is a method for lossless compression of floating‑point model checkpoints that pre‑computes a reusable setup based on exponent statistics. By grouping tensor chunks with similar exponent distributions, sharing Huffman codes, and packing recurring exponent tuples, it achieves 1.81–21.33× faster compression than baselines while preserving exact bit‑to‑bit reconstruction. The setup can be transferred across compatible architectures and reused during training, reducing GPU memory usage by up to 27.5% without affecting model outputs.

By Mart\'in Bravo, Samuel Horv\'ath, Gonzalo Navarro, Andr\'es Abeliuk
arXiv Machine Learning
Oct 16

LCT: Losslessly Compressed Tensors with GPU friendly execution for Training

The paper introduces Losslessly Compressed Tensors (LCT), a GPU‑friendly framework that repeatedly encodes and decodes tensors during training. LCT uses Huffman coding with precomputed codebooks to exploit redundancy in floating‑point data, achieving up to a 1.455× compression ratio. Experiments on models such as NanoGPT and Qwen3‑4B show memory savings of 24.6% and 23.8% respectively, enabling larger context lengths with only modest increases in step time.

By Max Zhu, Bohang Sun, Pietro Lio, Jialin Yu
arXiv AI
Oct 1

TensorHub: Scalable and Elastic Weight Transfer for LLM RL Training

arXiv:2604.09107v2 Announce Type: replace-cross Abstract: Modern LLM reinforcement learning (RL) workloads require a high-performance weight transfer system to scale training across heterogeneous com...

By Chenhao Ye, Huaizheng Zhang, Mingcong Han, Baoquan Zhong, Xiang Li, Qixiang Chen, Xinyi Zhang, Weidong Zhang, Kaihua Jiang, Wang Zhang, He Sun, Wencong Xiao, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau