Continuous Diffusion Scales Competitively with Discrete Diffusion for Language

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Yang, Zhihan, Guo, Wei, Zhang, Shuibai, Sahoo, Subham Sekhar, Chen, Yongxin, Vahdat, Arash, Mardani, Morteza, Thickstun, John
Format: Preprint
Publié: 2026
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866913141421506560
author Yang, Zhihan
Guo, Wei
Zhang, Shuibai
Sahoo, Subham Sekhar
Chen, Yongxin
Vahdat, Arash
Mardani, Morteza
Thickstun, John
author_facet Yang, Zhihan
Guo, Wei
Zhang, Shuibai
Sahoo, Subham Sekhar
Chen, Yongxin
Vahdat, Arash
Mardani, Morteza
Thickstun, John
contents While diffusion has drawn considerable recent attention from the language modeling community, continuous diffusion has appeared less scalable than discrete approaches. To challenge this belief we revisit Plaid, a likelihood-based continuous diffusion language model (DLM), and construct RePlaid by aligning the architecture of Plaid with modern discrete DLMs. In this unified setting, we establish the first scaling law for continuous DLMs that rivals discrete DLMs: RePlaid exhibits a compute gap of only $20\times$ compared to autoregressive models, outperforms Duo while using fewer parameters, and outperforms MDLM in the over-trained regime. We benchmark RePlaid against recent continuous DLMs: on OpenWebText, RePlaid achieves a new state-of-the-art PPL bound of $22.1$ among continuous DLMs and superior generation quality. These results suggest that continuous diffusion, when trained via likelihood, is a highly competitive and scalable alternative to discrete DLMs. Moreover, we offer theoretical insights to understand the advantage of likelihood-based training. We show that optimizing the noise schedule to minimize the ELBO's variance naturally yields linear cross-entropy (information loss) over time. This evenly distributes denoising difficulty without any case-specific time reparameterization. In addition, we find that optimizing embeddings via likelihood creates structured geometries and drives the most significant likelihood gain.
format Preprint
id arxiv_https___arxiv_org_abs_2605_18530
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Continuous Diffusion Scales Competitively with Discrete Diffusion for Language
Yang, Zhihan
Guo, Wei
Zhang, Shuibai
Sahoo, Subham Sekhar
Chen, Yongxin
Vahdat, Arash
Mardani, Morteza
Thickstun, John
Computation and Language
Artificial Intelligence
Machine Learning
While diffusion has drawn considerable recent attention from the language modeling community, continuous diffusion has appeared less scalable than discrete approaches. To challenge this belief we revisit Plaid, a likelihood-based continuous diffusion language model (DLM), and construct RePlaid by aligning the architecture of Plaid with modern discrete DLMs. In this unified setting, we establish the first scaling law for continuous DLMs that rivals discrete DLMs: RePlaid exhibits a compute gap of only $20\times$ compared to autoregressive models, outperforms Duo while using fewer parameters, and outperforms MDLM in the over-trained regime. We benchmark RePlaid against recent continuous DLMs: on OpenWebText, RePlaid achieves a new state-of-the-art PPL bound of $22.1$ among continuous DLMs and superior generation quality. These results suggest that continuous diffusion, when trained via likelihood, is a highly competitive and scalable alternative to discrete DLMs. Moreover, we offer theoretical insights to understand the advantage of likelihood-based training. We show that optimizing the noise schedule to minimize the ELBO's variance naturally yields linear cross-entropy (information loss) over time. This evenly distributes denoising difficulty without any case-specific time reparameterization. In addition, we find that optimizing embeddings via likelihood creates structured geometries and drives the most significant likelihood gain.
title Continuous Diffusion Scales Competitively with Discrete Diffusion for Language
topic Computation and Language
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2605.18530