aspireai.
PUBLIC EDITION

A tree drafter pairing a unigram proposer with a bigram selector decoded 5.8 to 6.9 times faster than autoregressive

AspireAI community · arXiv (cs.CL)
UBTree accelerates inference by drafting many candidate tokens at once and verifying them in a single target-model pass. It couples a unigram proposer, trained with the standard cross-entropy objective, with a lightweight bigram selector trained on a renormalized KL objective over high-temperature data - which broadens supervision beyond the greedy path and encourages plausible alternative branches that survive tree verification. Across seven standardized benchmarks with Qwen3-4B and Qwen3-8B it achieved an average speedup of 5.84x to 6.94x over autoregressive decoding, outperformed DARTree in all 28 head-to-head comparisons, and in production-scale evaluation came out ahead of frontier baselines such as DSpark. The limitation: the measurements are on Qwen3 models, and the extra compute the drafter costs is not broken out per configuration.
Read the story and explore more from the AspireAI community.
Discover more stories
Stay curious.
THE BIG PICTURE
A FRESH PERSPECTIVE
Research
One distance function matched sparse-autoencoder features across layers and compressed feature circuits into supernodes
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.
Swipe into something new
01 / 1729
The conversation continues
Explore Builds — projects by Kiran Adimatyam ↗
A fresh perspective changes everything.
ASPIREAI — STAY CURIOUS.