SwiftFusion: Scalable Sequence Parallelism for Distributed Inference of Diffusion Transformers on GPUs

Fuente: arXiv
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Main Authors: Yang, Jiacheng, Wu, Jun, Ding, Yaoyao, Xu, Zhiying, Wang, Yida, Pekhimenko, Gennady
Format: Preprint
Published: 2026
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author Yang, Jiacheng
Wu, Jun
Ding, Yaoyao
Xu, Zhiying
Wang, Yida
Pekhimenko, Gennady
author_facet Yang, Jiacheng
Wu, Jun
Ding, Yaoyao
Xu, Zhiying
Wang, Yida
Pekhimenko, Gennady
contents Diffusion Transformers (DiTs) have gained increasing adoption in high-quality image and video generation. As demand for higher-resolution images and longer videos increases, single-GPU inference becomes inefficient due to increased latency and large activation sizes. Current frameworks employ sequence parallelism (SP) techniques such as Ulysses Attention and Ring Attention to scale inference. However, these implementations have three primary limitations: (1) suboptimal communication patterns for network topologies on modern GPU machines, (2) latency bottlenecks from all-to-all operations in inter-machine communication, and (3) GPU sender-receiver synchronization and computation overheads from using two-sided communication libraries. To address these issues, we present StreamFusion, a topology-aware efficient DiT serving engine. StreamFusion incorporates three key innovations: (1) a topology-aware sequence parallelism technique that accounts for inter- and intra-machine bandwidth differences, (2) Torus Attention, a novel SP technique enabling overlapping of inter-machine all-to-all operations with computation, and (3) a one-sided communication implementation that minimizes GPU sender-receiver synchronization and computation overheads. Our experiments demonstrate that StreamFusion outperforms the state-of-the-art approach by an average of $1.35\times$ (up to $1.77\times$).
format Preprint
id arxiv_https___arxiv_org_abs_2601_20273
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle SwiftFusion: Scalable Sequence Parallelism for Distributed Inference of Diffusion Transformers on GPUs
Yang, Jiacheng
Wu, Jun
Ding, Yaoyao
Xu, Zhiying
Wang, Yida
Pekhimenko, Gennady
Distributed, Parallel, and Cluster Computing
Computer Vision and Pattern Recognition
Diffusion Transformers (DiTs) have gained increasing adoption in high-quality image and video generation. As demand for higher-resolution images and longer videos increases, single-GPU inference becomes inefficient due to increased latency and large activation sizes. Current frameworks employ sequence parallelism (SP) techniques such as Ulysses Attention and Ring Attention to scale inference. However, these implementations have three primary limitations: (1) suboptimal communication patterns for network topologies on modern GPU machines, (2) latency bottlenecks from all-to-all operations in inter-machine communication, and (3) GPU sender-receiver synchronization and computation overheads from using two-sided communication libraries. To address these issues, we present StreamFusion, a topology-aware efficient DiT serving engine. StreamFusion incorporates three key innovations: (1) a topology-aware sequence parallelism technique that accounts for inter- and intra-machine bandwidth differences, (2) Torus Attention, a novel SP technique enabling overlapping of inter-machine all-to-all operations with computation, and (3) a one-sided communication implementation that minimizes GPU sender-receiver synchronization and computation overheads. Our experiments demonstrate that StreamFusion outperforms the state-of-the-art approach by an average of $1.35\times$ (up to $1.77\times$).
title SwiftFusion: Scalable Sequence Parallelism for Distributed Inference of Diffusion Transformers on GPUs
topic Distributed, Parallel, and Cluster Computing
Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2601.20273