arXiv AI

WitCert: Sound Runtime Risk Observability and Gating for KV-Cache Quantization

arXiv:2607. 28699v1 Announce Type: cross Abstract: KV-cache quantization is validated today by offline benchmark averages; a deployed system cannot tell whether compression is damaging the request it is serving right now.

arXiv Machine Learning
Aug 31

A Method for Layer Bit-Width Allocation in LLM Quantization via Performance Maximization Under a Quality-Degradation Constraint

The paper introduces a method for allocating bit-widths to individual layers in Gemma-3-1B to maximize performance (latency reduction) while staying within a specified quality-degradation budget. Using a layer sensitivity profile from SA-PTQ and TensorRT-LLM, the authors evaluate 13 W8A8 variants on an RTX 5090, finding that FFN 5+5 with lm_head yields an 11.0% latency reduction with negligible quality loss. They also discuss trade-offs for Attention layers and propose further optimizations such as fused INT8 attention kernels and FP8 usage.

By Artem Safronov
arXiv Computation and Language
Sep 7

Quality Recovery for Quantized KV Caches via Low-Rank Attention Adaptation

The paper investigates how to recover language model quality lost when using low‑bit key–value caches for autoregressive decoding. By keeping the quantizer fixed and distilling the full‑precision cache behavior into low‑rank Q/K/V projection updates, the authors demonstrate that 4‑bit affine‑cache adapters recover roughly 54 % of the perplexity gap on TinyLlama‑1.1B and 76 % on Gemma‑4‑12B, while preserving most long‑context retrieval. Even a 2‑bit rank–token sweep can dramatically reduce TinyLlama’s perplexity, though it only partially restores retrieval performance.

By Seifeldin Abdellatif
arXiv AI
Sep 17

The Inference Engineering Pareto Atlas: Which Optimizations Dominate the Cost, Quality, and Latency Frontier?

The paper presents a Pareto atlas of LLM inference optimizations, mapping cost, quality, and latency trade‑offs for Qwen2.5‑7B‑Instruct on L4, A100, and H100 GPUs. Using 54 measured configurations and a calibrated simulator, it identifies 18 of 36 setups on the Pareto frontier, showing that combined methods outperform single ones. Quality tests reveal that AWQ 4bit and FP8 weights offer significant latency reductions while largely preserving accuracy, but naive FP8 KV caching fails to answer any questions correctly.

By Srikanta Datta Tumkur, Jay Iyer, Mehar Simhadri, Sai Pavan Kumar, Sai Kapil Kumar, Ramesh Nampelly