---
id: pr-sglang-15382
repo: sgl-project/sglang
pr: 15382
title: '[diffusion] Add Sage Attention 3 Support for sm 120 (RTX5090)'
author: ryang-max
date: '2025-12-19'
url: https://github.com/sgl-project/sglang/pull/15382
source_category: upstream-code
architectures:
- sm100
tags:
- attention
- kernel-fusion
- pipeline-stages
techniques:
- kernel-fusion
- pipeline-stages
hardware_features: []
kernel_types:
- attention
languages:
- cuda-cpp
- python
captured_at: '2026-04-27'
status: merged
merge_sha: 1e582488088f8cfe680bd59849e0683741f79f75
inclusion_reason: semantic match with file changes
changed_paths:
- python/sglang/multimodal_gen/configs/models/encoders/base.py
- python/sglang/multimodal_gen/runtime/models/dits/flux.py
- python/sglang/multimodal_gen/runtime/models/dits/flux_2.py
- python/sglang/multimodal_gen/runtime/models/dits/qwen_image.py
- python/sglang/multimodal_gen/runtime/pipelines_core/stages/denoising.py
- python/sglang/multimodal_gen/runtime/platforms/cuda.py
- python/sglang/multimodal_gen/runtime/utils/common.py
head_ref_oid: 86293106b35b613fef0d090b0d86b11097da30d6
artifact_dir: evidence/pull-bundles/sglang/gh-15382
---
# [diffusion] Add Sage Attention 3 Support for sm 120 (RTX5090)

- Repository: `sgl-project/sglang`
- PR: [15382](https://github.com/sgl-project/sglang/pull/15382)
- Decision: `semantic match with file changes`
- Reason: semantic match with file changes

## Changed Paths

- `python/sglang/multimodal_gen/configs/models/encoders/base.py`
- `python/sglang/multimodal_gen/runtime/models/dits/flux.py`
- `python/sglang/multimodal_gen/runtime/models/dits/flux_2.py`
- `python/sglang/multimodal_gen/runtime/models/dits/qwen_image.py`
- `python/sglang/multimodal_gen/runtime/pipelines_core/stages/denoising.py`
- `python/sglang/multimodal_gen/runtime/platforms/cuda.py`
- `python/sglang/multimodal_gen/runtime/utils/common.py`

## Evidence Bundle

`evidence/pull-bundles/sglang/gh-15382`
