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Tao, Zhikun, Jin, Fangyong, Zhao, Junping · Nov 10, 2026

Zhikun Tao, Fangyong Jin and Junping Zhao test KV cache reuse across model updates

Markdown · JSON · Original source

The authors investigate whether KV caches from an earlier language model can be reused after change, using four model updates and a detailed study of DeepSeek-V4-Flash to Flash-0731. They report that reused caches can retain useful task information without reproducing the updated model’s behavior: retrieval accuracy varies substantially across updates, from near-native performance to large losses. When source caches are already available, reuse yields median -to-first-token speedups of 2.10–5.08× on three longer-prefix QA . The authors introduce Functional Cache Divergence to compare next-token distributions from reused and native caches. Their results differ by task: reuse better preserves native behavior in natural-text continuation, while compatibility declines as prefixes grow in single-token retrieval tasks. Answer-margin analyses help explain why correct retrieval decisions can persist despite substantial internal state changes. But matching the first generated token does not ensure matching answer content or stopping behavior. The authors therefore distinguish task utility—whether a cache helps with a task—from fidelity to native inference—whether it reproduces the updated model’s behavior.

Headline and summary by Escape Meridian, prepared by Luna from the attributed source. A source check is not independent confirmation of the source’s claims.

arXiv cs.AIArticle · arxiv.orgOpen original source

Original source

cs.AI · Article

Source details

Original source date: Nov 10, 2026 (2026-11-10).

Date basis: Date basis not provided.

Added to Escape Meridian: 2026-11-12T03:18:45.439Z. First observed: 2026-11-11T05:00:56.447Z. Retrieved: 2026-11-12T03:17:52.566Z.

Referenced by

Recorded citations and public file attachments. A reference alone does not establish agreement or influence.

No public references recorded here yet.

Reference data (JSON)

Limits

The evidence is the abstract; it does not provide the experimental setup or detailed results for the individual model updates and . The reported case study includes DeepSeek-V4-Flash to Flash-0731; the abstract does not establish how the findings generalize to other models or update settings.

Open question

What features beyond agreement on the first generated token best indicate whether reused and native caches will produce the same answer content and stopping behavior?

Source-stated

The authors study direct KV cache reuse across four model updates, with a detailed case study of DeepSeek-V4-Flash to Flash-0731.

We investigate direct cache reuse across four model updates, with a detailed study of DeepSeek-V4-Flash to Flash-0731.

Source-stated

The authors report that reused caches can retain task information without faithfully reproducing updated-model behavior; retrieval accuracy varies widely across updates.

caches can retain useful task information without faithfully reproducing the updated model's behavior. Retrieval accuracy varies substantially across updates

Source-stated

With source caches available, reuse has median time-to-first-token speedups of 2.10–5.08× on three longer-prefix QA benchmarks.

reuse achieves median time-to-first-token speedups of $2.10$--$5.08\times$ on three longer-prefix QA benchmarks.

Source-stated

The authors introduce Functional Cache Divergence to compare next-token distributions produced with reused and native caches.

we introduce Functional Cache Divergence, which compares next-token distributions under reused and native caches.

Source-stated

The authors report that reuse better preserves native behavior in natural-text continuation, while compatibility declines as prefixes grow in single-token retrieval tasks.

Direct KV cache reuse better preserves native model behavior in natural-text continuation, whereas compatibility degrades with increasing prefix length in single-token retrieval tasks.

Source-stated

Agreement on the first generated token does not ensure agreement on answer content or stopping behavior.

even agreement on the first generated token does not ensure agreement in answer content or stopping behavior.

Source-stated

The authors treat task utility and fidelity to native inference as distinct evaluation criteria for cross-version KV cache reuse.

These findings establish task utility and fidelity to native inference as distinct criteria for evaluating cross-version KV cache reuse.

Source and contributor context

Tao, Zhikun, Jin, Fangyong, Zhao, Junping · Article author

These are credits stated by the source; they do not establish a profile match or authorship of every passage.

Source media

No suitable media was found by the supported page extraction.

Terms and references

Reference context selected by Escape Meridian; separate from source evidence. Entity mentions do not establish authorship, involvement or endorsement.

Model weights

The learned numbers that make up a trained model; publishing them lets others run it.

Benchmark

A defined set of tests used to compare systems. Results depend on the tasks and measures selected.

arXiv

arXiv is a research manuscript repository where authors share papers that may not yet have been peer reviewed.

TIME

TIME is a news magazine publishing reporting on world affairs, business, technology and the workers behind digital services.

Editorial provenance

Version 1. Publication ID: dd2f0ac0-a8fe-4fff-86d9-38a232094827.

Prepared by gpt-6-luna; grounding review by gpt-6-luna.

Source check: uncertain by anthropic/claude-opus-5.5 on 2026-11-12T03:18:45.439Z. This checks fidelity to the source, not whether its claims are independently true.

Editorial selection: accept; reasons: material_development.

Observation: 02c8af8a0924ff3baa55f8fab1113095b405bb2602ae461676baebad021c7c1e. Source text hash: f708721ef1daa3a0a1a8768949593b2d4fccea83f7bd5b2adc1520159056aa1d.

Revision and source-check history

Version 1 · 2026-11-12T03:18:45.439Z

Zhikun Tao, Fangyong Jin and Junping Zhao test KV cache reuse across model updates

The authors investigate whether KV caches from an earlier language model can be reused after change, using four model updates and a detailed study of DeepSeek-V4-Flash to Flash-0731. They report that reused caches can retain useful task information without reproducing the updated model’s behavior: retrieval accuracy varies substantially across updates, from near-native performance to large losses. When source caches are already available, reuse yields median -to-first-token speedups of 2.10–5.08× on three longer-prefix QA . The authors introduce Functional Cache Divergence to compare next-token distributions from reused and native caches. Their results differ by task: reuse better preserves native behavior in natural-text continuation, while compatibility declines as prefixes grow in single-token retrieval tasks. Answer-margin analyses help explain why correct retrieval decisions can persist despite substantial internal state changes. But matching the first generated token does not ensure matching answer content or stopping behavior. The authors therefore distinguish task utility—whether a cache helps with a task—from fidelity to native inference—whether it reproduces the updated model’s behavior.

Original source

cs.AI · Article

Source details

Original source date: Nov 10, 2026 (2026-11-10).

Date basis: Date basis not provided.

Added to Escape Meridian: 2026-11-12T03:18:45.439Z. First observed: 2026-11-11T05:00:56.447Z. Retrieved: 2026-11-12T03:17:52.566Z.

Limits

The evidence is the abstract; it does not provide the experimental setup or detailed results for the individual model updates and . The reported case study includes DeepSeek-V4-Flash to Flash-0731; the abstract does not establish how the findings generalize to other models or update settings.

Open question

What features beyond agreement on the first generated token best indicate whether reused and native caches will produce the same answer content and stopping behavior?

Source-stated

The authors study direct KV cache reuse across four model updates, with a detailed case study of DeepSeek-V4-Flash to Flash-0731.

We investigate direct cache reuse across four model updates, with a detailed study of DeepSeek-V4-Flash to Flash-0731.

Source-stated

The authors report that reused caches can retain task information without faithfully reproducing updated-model behavior; retrieval accuracy varies widely across updates.

caches can retain useful task information without faithfully reproducing the updated model's behavior. Retrieval accuracy varies substantially across updates

Source-stated

With source caches available, reuse has median time-to-first-token speedups of 2.10–5.08× on three longer-prefix QA benchmarks.

reuse achieves median time-to-first-token speedups of $2.10$--$5.08\times$ on three longer-prefix QA benchmarks.

Source-stated

The authors introduce Functional Cache Divergence to compare next-token distributions produced with reused and native caches.

we introduce Functional Cache Divergence, which compares next-token distributions under reused and native caches.

Source-stated

The authors report that reuse better preserves native behavior in natural-text continuation, while compatibility declines as prefixes grow in single-token retrieval tasks.

Direct KV cache reuse better preserves native model behavior in natural-text continuation, whereas compatibility degrades with increasing prefix length in single-token retrieval tasks.

Source-stated

Agreement on the first generated token does not ensure agreement on answer content or stopping behavior.

even agreement on the first generated token does not ensure agreement in answer content or stopping behavior.

Source-stated

The authors treat task utility and fidelity to native inference as distinct evaluation criteria for cross-version KV cache reuse.

These findings establish task utility and fidelity to native inference as distinct criteria for evaluating cross-version KV cache reuse.

Source and contributor context

Tao, Zhikun, Jin, Fangyong, Zhao, Junping · Article author

These are credits stated by the source; they do not establish a profile match or authorship of every passage.

Source media

No suitable media was found by the supported page extraction.

Terms and references

Reference context selected by Escape Meridian; separate from source evidence. Entity mentions do not establish authorship, involvement or endorsement.

Model weights

The learned numbers that make up a trained model; publishing them lets others run it.

Benchmark

A defined set of tests used to compare systems. Results depend on the tasks and measures selected.

arXiv

arXiv is a research manuscript repository where authors share papers that may not yet have been peer reviewed.

TIME

TIME is a news magazine publishing reporting on world affairs, business, technology and the workers behind digital services.

Editorial provenance

Version 1. Publication ID: dd2f0ac0-a8fe-4fff-86d9-38a232094827.

Prepared by gpt-6-luna; grounding review by gpt-6-luna.

Source check: uncertain by anthropic/claude-opus-5.5 on 2026-11-12T03:18:45.439Z. This checks fidelity to the source, not whether its claims are independently true.

Editorial selection: accept; reasons: material_development.

Observation: 02c8af8a0924ff3baa55f8fab1113095b405bb2602ae461676baebad021c7c1e. Source text hash: f708721ef1daa3a0a1a8768949593b2d4fccea83f7bd5b2adc1520159056aa1d.

uncertain · 2026-11-12T03:18:45.439Z · anthropic/claude-opus-5.5

Publication: dd2f0ac0-a8fe-4fff-86d9-38a232094827

attribution — pass: The title and summary correctly attribute the work to Zhikun Tao, Fangyong Jin and Junping Zhao. Findings are framed as the authors' reports rather than established facts. The arXiv submitter name (Zeke Tao) is a variant of the listed author and does not conflict with the attribution.

Authors:Zhikun Tao, Fangyong Jin, Junping Zhao

summary — uncertain: The summary is faithful, but it never states why reuse is attempted. The abstract gives the motivation: reuse could avoid repeating computation of shared context. Without that, a non-specialist meets 'KV caches' (stored intermediate model state for prior text), 'time-to-first-token' and 'native caches' with no stated purpose or stake. Smallest repair: in the opening sentence, add the source's motivation that reuse could avoid recomputing shared context, and check that these terms have term-library tooltips. The question is substantive and follows from the evidence.

Reusing key--value (KV) caches across language model updates could avoid repeated computation of shared context

date — pass: originalPublished is 2026-11-10, which matches the arXiv v1 submission date. The feed date of 2026-11-11 is correctly not used.

[Submitted on 10 Nov 2026]

support — pass: Every claim is quoted from the abstract with matching scope: four updates, the 2.10–5.08× median speedup conditioned on caches already being available, the task-dependent results, and the first-token caveat. The reading adds no unsupported benefits or costs. Its limitations correctly note that the evidence is abstract-only and that generalization is unclear.

With source caches already available, reuse achieves median time-to-first-token speedups of $2.10$--$5.08\times$ on three longer-prefix QA benchmarks.

media — pass: The selected media is the verified direct arXiv abstract page for this paper. It is the most direct way to access the source.

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