KV缓存压缩是长上下文推理的关键瓶颈，做LLM推理优化的开发者可以直接参考α方法——它用一行修改就打败了七种复杂方案，值得在自家模型上试试。
该研究系统评估了七种KV缓存压缩机制在数学推理任务上的表现，发现所有现有方法在小预算下均被拒绝。作者提出一种名为α的简单修改，通过引入多样性惩罚项替代传统argmax-top-k选择，在Qwen-7B和Llama-8B模型上，在64和128预算下，α在两项测试中显著优于基线。该发现表明，最小化的评分修改比复杂的结构重设计更有效，且严格的实验协议使这一不对称性得以显现。
Minimal-Intervention KV Retention: A Design-Space Study and a Diversity-Penalty Survivor
KV-cache compression at small budgets is a crowded design space spanning cache representation, head-wise routing, compression cadence, decoding behavior, and within-budget scoring. We study seven mechanisms across these five families under matched mean cache on long-form mathematical reasoning (MATH-500~\cite{hendrycks2021math}) with two distilled-reasoning models (Qwen-7B and Llama-8B variants of DeepSeek-R1-Distill~\cite{deepseek2025r1}) at budgets $b \in \{64, 128\}$. All seven were rejected. We then propose $α$, a one-function modification to the TriAttention~\cite{mao2026triattention} retention scorer that replaces argmax-top-$k$ with greedy facility-location-inspired selection under a V-space redundancy penalty controlled by a single weight $λ$. A pre-registered protocol tunes $λ$ on a frozen development split and confirms on a disjoint held-out split; with $λ= 0.5$, $α$ clears Bonferroni on two of the four (model, budget) cells (Qwen $b{=}128$ and Llama $b{=}64$), no cell is significantly negative, and the pre-registered Branch~A triggers. The finding is asymmetric: a minimal scoring modification beat heavier structural redesigns in this regime, and the combined matched-memory, sympy-graded, held-out confirmation protocol is the evidence standard that made the asymmetry visible.