Deep dive: KV caching for flow-based image generation, with intuition, pseudocode and benchmarks

RisingSayak · x · 2026-10-07

Inspired by the KV caching mechanism in QwenImage 2.1 (and noting Flux.2-Klein-KV likely pioneered it for reference image tokens), the author published a long-form piece on KV caching in flow models for image generation.
It covers intuition, commentary, implementation details, benchmarks, and quirky experiments, following Karpathy's teaching style: build intuition first, then provide implementable pseudocode.
Benchmarks focus on the speed-memory trade-off. Additional findings: combining traditional diffusion caching (e.g. TaylorSeer) with KV caching causes noticeable quality degradation; KV-caching text projections in Flux.2-Klein-KV looks viable but needs further validation.

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