FlashMap drafts a whole token block in one forward pass with a continuous flow map, and reports up to 6.1x lossless decoding speedup on Qwen3-8B
AspireAI community · arXiv
*Block-diffusion drafters propose a block of tokens in one pass but score each position independently, so they throw away the dependencies between the tokens they are proposing.* FlashMap replaces that with a continuous flow map conditioned on the target model's hidden states, which jumps from Gaussian noise to the entire token block in one network evaluation and can model how the positions relate to each other. On Qwen3-8B it is faster than a matched DFlash baseline on every benchmark, with 7 percent higher average speedup and up to 6.1x lossless acceleration, meaning the target model still verifies every drafted token and the output distribution is unchanged. The drafter weights are public - 500M parameters for Qwen3-8B and 475M for Qwen3-4B - with working vLLM and SGLang plugins, so this is a serving change rather than a paper you can only read. The honest caveats: the paper went up on arXiv on October 17, the headline number comes from one model family, and the project's own README warns that greedy outputs can diverge from the target under bfloat16 because of near-tie rounding in the batched verification pass, which it says to check with float32.
Read the story and explore more from the AspireAI community.
Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.