DCKV trained an end-to-end KV-cache codec that stores a compressed token in over 55 times fewer bytes than bf16 for at most 1.8 points of long-context accuracy
AspireAI community · arXiv (2610.36950)
Hybrid language models keep a key-value cache only in their few full-attention layers, but that cache still grows with the prompt and has to be stored or moved to reuse it. DCKV treats the cache as something to compress with a learned codec rather than a set of numbers to quantize after the fact: its transform, quantizer and entropy models are conditioned on the prompt tokens and on already-decoded neighbouring positions, and all three are trained end to end against a frozen language model for both code length and output change. On Qwen3.5-2B the authors report storing a compressed token in more than 55 times fewer bytes than bf16 at a loss of at most 1.8 points on three long-context benchmarks, and more than 100 times fewer bytes at a loss of at most 3.6 points. The limitation is scope: every number comes from one 2B model and a codec trained against that specific frozen model, and the paper does not report transfer to other families.
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