The paper investigates when attention maps can be compressed beyond simple sparsity, arguing that large weights alone do not guarantee compressibility. It introduces metrics such as global score gaps and weighted sums of omitted values to determine token retention for a target mass, and presents a retrieval–aggregation model to predict the impact of truncation. Based on these insights, the authors propose CertKV, a training‑free compressor that allocates a tail‑summary slot per head and distributes remaining slots according to value dispersion, achieving strong performance across several benchmarks.
By Chiwun Yang, Xiaoyu Li
The paper introduces Random Attention, a method that evicts KV cache entries uniformly at random within each attention head while preserving the prompt. Experiments on four models and six reasoning tasks show that this simple strategy matches the performance of the best existing eviction methods and achieves 32‑43% higher throughput in vLLM deployments. The authors explain that the prompt is the most fragile cache component and that reasoning traces are redundantly stored across text and attention heads, making a selection score unnecessary.
By Heng Wang, Jielin Qiu, Wenting Zhao, Cheng Qian, Liangwei Yang, Jiawei Han, Heng Ji, Silvio Savarese, Shelby Heinecke, Huan Wang
arXiv:2607. 15498v1 Announce Type: cross Abstract: The key-value (KV) cache is the main memory bottleneck in long-context large language model (LLM) inference.
By Shahrzad Esmat, Dhawal Shah, Ali Jannesari
ValueDiff introduces a value‑geometric KV cache eviction strategy for large language models that suppress attention sinks. It ranks tokens by the L2 deviation of their value vectors from the cache mean, a score that aligns with minimal‑disturbance eviction under a max‑entropy assumption. Across several benchmarks—RULER, LongBench, and MATH‑500—ValueDiff consistently retains a higher proportion of useful tokens than prior methods, especially under tight cache budgets.
By Junyoung Park, Jungwook Choi, Mingu Lee
arXiv:2609.30738v1 Announce Type: new
Abstract: KV cache eviction methods such as SnapKV and PyramidKV rank tokens solely by mean attention over a small observation window. We study a unified score,...
By Tianfang Xie, Wei Zhu
The paper introduces Random Attention, a method that evicts KV cache entries uniformly at random within each attention head while preserving the prompt. It demonstrates that this simple strategy matches or surpasses more complex eviction schemes across four models and six reasoning tasks, achieving 32‑43% higher throughput in vLLM deployments. Experiments reveal that the prompt is the most fragile cache component and that redundancy in the reasoning trace across text and attention heads protects against random eviction, eliminating the need for a selection score.
The paper introduces Draft‑Guided Eviction (DGE), a training‑free KV‑cache compression technique that postpones token eviction until after drafting the first two answer tokens, thereby preserving the cache entries needed for the answer trajectory. Unlike prior methods that focus on optimizing what to keep, DGE changes the timing of eviction, allowing existing compression schemes such as SnapKV, H2O, and PyramidKV to be applied without altering their eviction scores. Experiments show DGE consistently outperforms previous approaches across multiple instruct‑tuned models, achieving near‑full‑cache performance on LongBench and demonstrating that the improvement stems from trajectory anchoring rather than changes in cache selection.
By Haeyong Kang, Chang D. Yoo
arXiv:2608. 01247v1 Announce Type: cross Abstract: Query-agnostic KV cache eviction compresses a context once and reuses the resulting cache for arbitrary future queries, but performance can collapse under tight budgets.
By Changwoo Baek, Seungjun Shin, Kyeongbo Kong
The paper introduces a method to incorporate attention bias directly into the keys of compacted KV caches, enabling standard kernels like FlashAttention and vLLM to use these folded caches without modification. By fitting a bias along a closed‑form direction per head, the approach preserves the cache size and head dimension while bounding output error based on query projections. Experiments on Qwen3 and Llama‑3.1 models show that the folded caches match or exceed the accuracy of the original Attention Matching method across various benchmarks, with comparable or lower KL divergence to full caches.
By Utkarsh Kanwat
Page-EntroKV is a new KV‑cache eviction framework designed for grouped‑query attention (GQA) in long‑context autoregressive language models. It pools token importance scores across query heads within each physical group using sink‑isolated Renyi‑2 entropy, then projects these pooled scores onto page frames and performs eviction at the hardware tuple level. The authors prove theoretical guarantees on union overhead, budget preservation, and needle‑retention, and demonstrate on a Qwen2.5‑1.5B‑Instruct pilot that Page‑EntroKV achieves exact union overhead control, eliminates sink masquerade, and retains 100% of critical tokens compared to mean‑pooling baselines.
By Inbasekaran S
KV$^2$ is a query‑agnostic key‑value cache compression technique that selectively reconstructs only informative in‑context tokens using a lightweight proxy scorer before final eviction scoring. On benchmarks such as RULER, Needle‑in‑a‑Haystack, and LongBench, KV$^2$ outperforms baseline methods, especially under tight memory budgets, achieving higher scores with lower runtime and peak memory than full‑context reconstruction. The approach demonstrates that reusable KV‑cache compression can avoid reprocessing the entire prompt while maintaining quality.
By Johannes Wesch, Danni Liu, Jan Niehues
The paper introduces EpiKV, an epiphany‑aware key–value cache eviction strategy that avoids using the attention matrix. It leverages hidden‑state shifts and recent query–key relevance to rank cached tokens, matching or surpassing the performance of existing attention‑based eviction methods while remaining compatible with fast inference kernels. Experiments on multiple benchmarks show that EpiKV improves inference throughput without sacrificing accuracy.
By Steven Kolawole, Virginia Smith