Hold Onto That Thought: Assessing KV Cache Compression On Reasoning

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Liu, Minghui, Palnitkar, Aadi, Rabbani, Tahseen, Jae, Hyunwoo, Sang, Kyle Rui, Yao, Dixi, Shabihi, Shayan, Zhao, Fuheng, Li, Tian, Zhang, Ce, Huang, Furong, Zhang, Kunpeng
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909959421165568
author Liu, Minghui
Palnitkar, Aadi
Rabbani, Tahseen
Jae, Hyunwoo
Sang, Kyle Rui
Yao, Dixi
Shabihi, Shayan
Zhao, Fuheng
Li, Tian
Zhang, Ce
Huang, Furong
Zhang, Kunpeng
author_facet Liu, Minghui
Palnitkar, Aadi
Rabbani, Tahseen
Jae, Hyunwoo
Sang, Kyle Rui
Yao, Dixi
Shabihi, Shayan
Zhao, Fuheng
Li, Tian
Zhang, Ce
Huang, Furong
Zhang, Kunpeng
contents Large language models (LLMs) have demonstrated remarkable performance on long-context tasks, but are often bottlenecked by memory constraints. Namely, the KV cache, which is used to significantly speed up attention computations, grows linearly with context length. A suite of compression algorithms has been introduced to alleviate cache growth by evicting unimportant tokens. However, several popular strategies are targeted towards the prefill phase, i.e., processing long prompt context, and their performance is rarely assessed on reasoning tasks requiring long decoding. In particular, short but complex prompts, such as those in benchmarks like GSM8K and MATH500, often benefit from multi-step reasoning and self-reflection, resulting in thinking sequences thousands of tokens long. In this work, we benchmark the performance of several popular compression strategies on long-reasoning tasks. For the non-reasoning Llama-3.1-8B-Instruct, we determine that no singular strategy fits all, and that performance is heavily influenced by dataset type. However, we discover that H2O and our decoding-enabled variant of SnapKV are dominant strategies for reasoning models, indicating the utility of heavy-hitter tracking for reasoning traces. We also find that eviction strategies at low budgets can produce longer reasoning traces, revealing a tradeoff between cache size and inference costs.
format Preprint
id arxiv_https___arxiv_org_abs_2512_12008
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Hold Onto That Thought: Assessing KV Cache Compression On Reasoning
Liu, Minghui
Palnitkar, Aadi
Rabbani, Tahseen
Jae, Hyunwoo
Sang, Kyle Rui
Yao, Dixi
Shabihi, Shayan
Zhao, Fuheng
Li, Tian
Zhang, Ce
Huang, Furong
Zhang, Kunpeng
Computation and Language
Artificial Intelligence
Performance
Large language models (LLMs) have demonstrated remarkable performance on long-context tasks, but are often bottlenecked by memory constraints. Namely, the KV cache, which is used to significantly speed up attention computations, grows linearly with context length. A suite of compression algorithms has been introduced to alleviate cache growth by evicting unimportant tokens. However, several popular strategies are targeted towards the prefill phase, i.e., processing long prompt context, and their performance is rarely assessed on reasoning tasks requiring long decoding. In particular, short but complex prompts, such as those in benchmarks like GSM8K and MATH500, often benefit from multi-step reasoning and self-reflection, resulting in thinking sequences thousands of tokens long. In this work, we benchmark the performance of several popular compression strategies on long-reasoning tasks. For the non-reasoning Llama-3.1-8B-Instruct, we determine that no singular strategy fits all, and that performance is heavily influenced by dataset type. However, we discover that H2O and our decoding-enabled variant of SnapKV are dominant strategies for reasoning models, indicating the utility of heavy-hitter tracking for reasoning traces. We also find that eviction strategies at low budgets can produce longer reasoning traces, revealing a tradeoff between cache size and inference costs.
title Hold Onto That Thought: Assessing KV Cache Compression On Reasoning
topic Computation and Language
Artificial Intelligence
Performance
url https://arxiv.org/abs/2512.12008