KV-cache compression

Quest

Quest: Query-Aware Sparsity for Efficient Long-Context LLM Inference

Superseded baseline#6 of 234 most-superseded · first seen Jun 16, 2024

Superseded — cited as a baseline and beaten by newer methods

13 papers critique it · 16 beat it on benchmarks

What papers say

Verbatim critique sentences, each from a paper that cites Quest as a baseline.

this line of work does not mitigate the memory footprint, thereby limiting the batch size and preventing accommodation of extremely long contexts (e.g., 1M tokens)
ShadowKV: KV Cache in Shadows for High-Throughput Long-Context LLM Inference
Despite the relatively low overhead, Quest lacks sophisticated design in the retrieval strategy, thus suffers from noticeable performance degradation.
A$^2$ATS: Retrieval-Based KV Cache Reduction via Windowed Rotary Position Embedding and Query-Aware Vector Quantization
This reduces compute and I/O while mostly preserving accuracy, though memory use remains unchanged.
FlexiCache: Leveraging Temporal Stability of Attention Heads for Efficient KV Cache Management
Instead of leveraging the attention patterns of previous tokens, these methods build specialized kernel to approximate attention and identify critical tokens.
RefreshKV: Updating Small KV Cache During Long-form Generation
Quest is sensitive to the page size, and the accuracy significantly drops with large page sizes and small budgets, as shown in fig:block_size.
AttentionPredictor: Temporal Patterns Matter for KV Cache Compression
Quest stores the entire KV cache in GPU memory with limited capacity, restricting support for long context lengths and large batch sizes.
FreeKV: Boosting KV Cache Retrieval for Efficient LLM Inference
However, methods like Quest~tang2024quest and SparQ~ribar2024sparq encounter memory limitations when attempting to store all tokens on the GPU.
TailorKV: A Hybrid Framework for Long-Context Inference via Tailored KV Cache Optimization
However, it fails to reduce memory usage and suffers from accuracy degradation.
HeteroCache: A Dynamic Retrieval Approach to Heterogeneous KV Cache Compression for Long-Context LLM Inference
While effective, most methods either discard unused tokens too early or require full cache for scoring.
PiKV: KV Cache Management System for Mixture of Experts
selective loading fails to reduce the memory footprint
MemShare: Memory Efficient Inference for Large Reasoning Models through KV Cache Reuse
since pages are divided simply by textual positions of tokens, internal fragmentation becomes an issue: a recalled page may contain unimportant tokens, wasting budget that could be allocated to truly important tokens
ClusterKV: Manipulating LLM KV Cache in Semantic Space for Recallable Compression
In fact, to efficiently perform page selection, the method requires storing additional page representations, resulting in a slight memory overhead rather than savings.
Inference-Time Hyper-Scaling with KV Cache Compression

Beaten on benchmarks

Head-to-head results where a newer method reports beating Quest. Values are copied from the source paper's tables — verify against the cited paper.

What to use instead

Recent methods in the same sub-problem, not yet superseded in the knowledge base — arXiv benchmark leaders, not vetted production recommendations.