Spend Bytes on Breadth: Precision-Count Trade-offs for Decode-Time KV Compression in Long Chain-of-Thought Reasoning
On the map: LLM reasoning → Test-time compute and efficient thinking
Abstract (arXiv)
Reasoning models write most of their KV cache while decoding long chains of thought (CoT), so the cache has to be compressed online under a fixed memory budget. Decode-time methods mostly decide which tokens to evict. We ask how a fixed byte budget should be split between the number of cached tokens and their precision. BreadthKV spends the bytes on more tokens at low precision, combining quantization with eviction, and picks the bit-width for each model and budget with a 60-problem end-to-end calibration, since offline attention error does not predict it reliably. On three reasoning models and four math and science benchmarks, it scores above eviction alone in 17 of 18 settings and produces shorter outputs. Much of what eviction loses comes from derailed runs, which keep reasoning until the length cap without reaching an answer. On Qwen3-8B at our tightest budget, eviction sends 91% of AIME samples to the cap and BreadthKV 40%. Under the same protocol, BreadthKV is statistically indistinguishable from a joint rate-distortion allocator (RDKV) that uses 27% more KV memory-time, and it outperforms our re-implementation of ThinKV.
Key facts. No citing papers in the map yet (data through 7 Oct 2026). Placed in Test-time compute and efficient thinking, one of 17 directions in LLM reasoning. Builds on 52 of its 61 references that are in the map. First posted on arXiv 5 Oct 2026.
Builds on
52 of 61 references.
Closest ancestors · 22
Same direction, newest first
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- 2026ReasonAlloc: Hierarchical Decoding-Time KV Cache Budget Allocation for Reasoning Models9 Jun
- 2026Value-Aware Stochastic KV Cache Eviction for Reasoning Models2 Jun
- 2026KVarN: Variance-Normalized KV-Cache Quantization Mitigates Error Accumulation in Reasoning Tasks2 Jun
- 2026TriAttention: Efficient Long Reasoning with Trigonometric KV Compression6 Apr
- 2025MixKVQ: Query-Aware Mixed-Precision KV Cache Quantization for Long-Context Reasoning22 Dec
- 2025Wait, Wait, Wait... Why Do Reasoning Models Loop?15 Dec
- 2025G-KV: Decoding-Time KV Cache Eviction with Global Attention29 Nov
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- 2025Lethe: Layer- and Time-Adaptive KV Cache Pruning for Reasoning-Intensive LLM Serving8 Nov
- 2025Not All Bits Are Equal: Scale-Dependent Memory Optimization Strategies for Reasoning Models13 Oct
- 2025Which Heads Matter for Reasoning? RL-Guided KV Cache Compression9 Oct
- 2025ThinKV: Thought-Adaptive KV Cache Compression for Efficient Reasoning Models1 Oct
- 2025LazyEviction: Lagged KV Eviction with Attention Pattern Observation for Efficient Long Reasoning19 Jun
- 2025SeerAttention-R: Sparse Attention Adaptation for Long Reasoning10 Jun
- 2025R-KV: Redundancy-aware KV Cache Compression for Reasoning Models30 May
- 2025PM-KVQ: Progressive Mixed-precision KV Cache Quantization for Long-CoT LLMs24 May
- 2025RaaS: Reasoning-Aware Attention Sparsity for Efficient LLM Reasoning16 Feb
- 2025Semantic Integrity Matters: Benchmarking and Preserving High-Density Reasoning in KV Cache Compression4 Feb
Other references · 30
- 2021Measuring Mathematical Problem Solving With the MATH Datasetcited by 5,203
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- 2023FlashAttention-2: Faster Attention with Better Parallelism and Work Partitioningcited by 2,551
- 2023Efficient Streaming Language Models with Attention Sinkscited by 2,115
- 2024SnapKV: LLM Knows What You are Looking for Before Generationcited by 848
- 2024KIVI: A Tuning-Free Asymmetric 2bit Quantization for KV Cachecited by 604
- 2024QuaRot: Outlier-Free 4-Bit Inference in Rotated LLMscited by 598
- 2024KVQuant: Towards 10 Million Context Length LLM Inference with KV Cache Quantizationcited by 571
- 2024PyramidKV: Dynamic KV Cache Compression based on Pyramidal Information Funnelingcited by 420
- 2024Ada-KV: Optimizing KV Cache Eviction by Adaptive Budget Allocation for Efficient LLM Inferencecited by 230
- 2024PyramidInfer: Pyramid KV Cache Compression for High-throughput LLM Inferencecited by 148
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- 2024ShadowKV: KV Cache in Shadows for High-Throughput Long-Context LLM Inferencecited by 132
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- 2024No Token Left Behind: Reliable KV Cache Compression via Importance-Aware Mixed Precision Quantizationcited by 99
- 2024ZipCache: Accurate and Efficient KV Cache Quantization with Salient Token Identificationcited by 86
- 2024KV Cache Compression, But What Must We Give in Return? A Comprehensive Benchmark of Long Context Capable Approachescited by 43
- 2025KVTuner: Sensitivity-Aware Layer-Wise Mixed-Precision KV Cache Quantization for Efficient and Nearly Lossless LLM Inferencecited by 36
- 2025xKV: Cross-Layer KV-Cache Compression via Aligned Singular Vector Extractioncited by 13
- 2025KV Cache Transform Coding for Compact Storage in LLM Inferencecited by 11
- 2026STAR-KV: Low-Rank KV Cache Compression via Soft Thresholding for Adaptive Rank Controlcited by 11
- 2024More Tokens, Lower Precision: Towards the Optimal Token-Precision Trade-off in KV Cache Compressioncited by 10
- 2025Kitty: Accurate and Efficient 2-bit KV Cache Quantization with Dynamic Channel-wise Precision Boostcited by 8
- 2026Don't Waste Bits! Adaptive KV-Cache Quantization for Lightweight On-Device LLMscited by 7
- 2025Value-Guided KV Compression for LLMs via Approximated CUR Decompositioncited by 6
- 2026RDKV: Rate-Distortion Bit Allocation for Joint Eviction and Quantization of the KV Cachecited by 4
- 2026TriAxialKV: Toward Extreme Low-Precision KV-Cache Quantization for Agentic Inference Taskscited by 3
- 2026SPHERICAL KV: Angle-Domain Attention and Rate-Distortion Retention for Efficient Long-Context Inferencecited by 2
- 2026Does Accuracy Equal Evidence? Reasoning Faithfulness under KV Cache Compressioncited by 2
- 2026QEvict: Recoverable Quantized KV Eviction for Attention-Drift-Robust Long-Context Decodingcited by 2
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