Triton + SageAttention (ComfyUI acceleration)

> See also comfyui-launch-flags for the full > attention / VRAM / cache flag matrix. Note the Z-Image exception: Z-Image is > broken under --use-sage-attention → launch it with > --use-pytorch-cross-attention instead.

Overview

Two optional accelerators that many modern video graphs (especially kijai's ComfyUI-WanVideoWrapper) reference by default:

• SageAttention (import sageattention) — a quantized attention kernel.

Selected via a node's attention_mode = sageattn (WanVideoWrapper) or ComfyUI's --use-sage-attention startup flag. ~20–40% faster sampling on supported NVIDIA GPUs.

• Triton — the GPU kernel compiler that inductor torch.compile needs.

WanVideoWrapper's WanVideoTorchCompileSettings (and any torch.compile/ inductor node) compiles the model through Triton for another speedup.

> ⚠️ The risk. Both are version-locked to your exact torch + CUDA + python. > A wrong wheel doesn't just fail to install — it can break the torch install > (mismatched CUDA DLLs, ImportError, or silent NaNs). And the failure mode of > not having them is a hard crash before any sampling: > ValueError: Can't import SageAttention: No module named 'sageattention', or > compile errors / triton: unavailable in the startup log. This is exactly the > video-extend TRAP 5.

> ✅ Therefore the default is: get a working render FIRST with the > sdpa / no-compile fallback, > then OFFER to install acceleration for speed. Never silently run a > torch-breaking install to "fix" a workflow — fall back, render, then ask.

> ⚠️ Verification note (June 2026). Wheel sources, the triton↔torch table, and > the live attention_mode enum below were verified against > woct0rdho/triton-windows, woct0rdho/SageAttention releases, and > WanVideoWrapper's nodes (see Sources). Versions move fast — always > re-read the live torch/CUDA/python first (commands below) and pick the wheel > that matches; flag anything you can't confirm rather than guessing.

Decide first: do you even need them?

Workflow crashes "No module named 'sageattention'"  ──┐
  or "triton: unavailable" / torch.compile error     ─┤
                                                       ▼
              1. APPLY THE SDPA / NO-COMPILE FALLBACK  → render works now
                                                       ▼
              2. OFFER acceleration:
                 "Want me to install Triton + SageAttention for ~20–40%
                  faster sampling? It's a version-matched install that
                  touches your torch env — I'll verify torch/CUDA/python
                  first and can roll back."
                                                       ▼
              3. Only on YES → install per-OS below → verify → re-enable
                 sageattn + torch.compile in the workflow.

Mac (no CUDA): skip the install entirely, the answer is always sdpa/MPS.

The safe sdpa / no-compile fallback (DO THIS FIRST)

When Triton/SageAttention aren't installed, make the workflow run unaccelerated but correct by switching attention to sdpa (PyTorch's built-in scaled dot-product attention — always available, no extra deps) and removing the torch.compile/inductor wiring.

WanVideoWrapper (the common case):

1. On every WanVideoModelLoader set attention_mode → sdpa.

• Confirmed enum values: sdpa, flash_attn_2, flash_attn_3, sageattn,

sparse_sage_attention. The examples ship with sageattn; sdpa is the universal safe one.

1. Disconnect WanVideoTorchCompileSettings from each loader's compile_args

input (or delete/bypass the node). No compile = no Triton needed.

1. (If present) bypass any WanVideoSetRadialAttention /

sparse_sage_attention node — those also route through SageAttention.

Generic ComfyUI: don't launch with --use-sage-attention; bypass any TorchCompileModel / inductor node.

This costs you speed, not quality. Use create_workflow (action:"modify") / the panel's strip-and-re-point flow to flip the widget and drop the link, then enqueue. Once it renders, offer the install.

> Cross-ref: video-extend documents this exact fix > as TRAP 5 for the Pusa extension graph (both WanVideoModelLoaders → > attention_mode=sdpa, disconnect WanVideoTorchCompileSettings).

Windows install (the priority)

Windows has no official Triton or SageAttention build. You use community prebuilt wheels, and they must match torch + CUDA + python exactly. The panel agent has a shell (Bash for Claude / exec for Codex) — use it to run these in the correct python, never the system python.

Step 1 — find the RIGHT python (NOT system python)

ComfyUI on Windows comes in three flavors; each has its own python whose pip you must target:

| Variant | Where its python lives | How to invoke pip | |---|---|---| | Desktop (standalone) | a standalone-env\ (or venv) beside the install, e.g. C:\Users\<you>\ComfyUI-Installs\ComfyUI\standalone-env\python.exe | "<install>\standalone-env\python.exe" -m pip ... | | Portable | ComfyUI_windows_portable\python_embeded\python.exe | "<...>\python_embeded\python.exe" -m pip ... | | Manual venv | the venv you created (venv\Scripts\python.exe) | activate it, then python -m pip ... |

Detect it from the live server — the surest way to hit the same python ComfyUI runs on:

• install_comfyui (action:"environment") / get_system_stats report embedded_python (true →

Portable), the python version and the pytorch_version (e.g. 2.10.0+cu130).

• Inspect the running process's argv (from get_system_stats) — the path to

main.py reveals the install root; its sibling standalone-env / python_embeded holds the python.

• Last resort, ask the user for their ComfyUI folder.

> ⚠️ Installing into the wrong python (e.g. a global pip install) is the #1 > Windows mistake: the package lands somewhere ComfyUI never imports from, so the > loader still crashes "No module named 'sageattention'". Always use > "<that python>" -m pip.

Step 2 — read the installed torch + CUDA + python

Run with the python you just found:

bash
"<python>" -c "import sys, torch; print(sys.version.split()[0], torch.__version__, torch.version.cuda)"

Example live output on this machine: 3.13.12 2.10.0+cu130 13.0 → python 3.13, torch 2.10, CUDA line cu130. You'll pick wheels for that triple.

Step 3 — install triton-windows (matched to torch)

Source: woct0rdho/triton-windows (the canonical Windows Triton fork; also on PyPI as triton-windows). The pin is just an upper bound — pip resolves the right build for your torch:

bash
"<python>" -m pip install -U "triton-windows<3.7"

Why <3.7: each torch minor pins a Triton minor. Verified table:

| PyTorch | triton-windows | constraint to use | |---|---|---| | 2.7 | 3.3 | "triton-windows<3.4" | | 2.8 | 3.4 | "triton-windows<3.5" | | 2.9 | 3.5 | "triton-windows<3.6" | | 2.10 | 3.6 | "triton-windows<3.7" |

(torch 2.6 or older → triton 3.2 or earlier.) Pick the row for your torch.

• CUDA toolkit: since triton-windows 3.2.0.post11 a minimal CUDA toolchain

is bundled in the wheel — you do NOT need a separate CUDA Toolkit install for Triton itself. (Triton 3.3–3.6 bundle the CUDA 12.8 line; works against cu12x/ cu13x torch.)

• MSVC / vcredist: Triton compiles C++ at runtime, so it needs the MSVC

toolchain + "Visual C++ Redistributable 2015–2022" present. A TinyCC is bundled (since 3.2.0.post13) which covers many cases, but installing the Visual Studio Build Tools (C++ workload) + latest vcredist is the reliable fix if you hit compiler errors (see Traps).

• Embedded/Portable python only: the embedded distro ships without C headers,

so Triton can't compile. Download the matching python_<ver>_include_libs.zip from the triton-windows releases and copy its include and libs (note: libs, not lib) folders into python_embeded\. The Desktop standalone-env usually already has these.

Step 4 — install SageAttention (prebuilt wheel, matched to torch+CUDA)

Strongly prefer the prebuilt wheel — building from source needs the full CUDA Toolkit (nvcc) + MSVC and frequently fails on Windows. Source: woct0rdho/SageAttention releases (Windows wheels; v2 = SageAttention 2.x).

Latest verified tag: v2.2.0-windows.post5, with these four wheels (all cp310-abi3 → work on python 3.10 through 3.13+ via the stable ABI; one wheel covers all those pythons):

| Wheel filename | For | |---|---| | sageattention-2.2.0+cu128torch2.9.1.post5-cp310-abi3-win_amd64.whl | CUDA 12.8 line, torch 2.9.x | | sageattention-2.2.0+cu128torch2.10.0andhigher.post5-cp310-abi3-win_amd64.whl | CUDA 12.8 line, torch ≥2.10 | | sageattention-2.2.0+cu130torch2.9.1.post5-cp310-abi3-win_amd64.whl | CUDA 13.0 line, torch 2.9.x | | sageattention-2.2.0+cu130torch2.10.0andhigher.post5-cp310-abi3-win_amd64.whl | CUDA 13.0 line, torch ≥2.10 |

Pick by your CUDA line (cu128 vs cu130 — from torch.version.cuda: 12.8 → cu128, 13.0 → cu130) and torch minor. For the live machine above (torch 2.10.0+cu130, py3.13) → the last wheel. Install by full URL:

bash
"<python>" -m pip install "https://github.com/woct0rdho/SageAttention/releases/download/v2.2.0-windows.post5/sageattention-2.2.0+cu130torch2.10.0andhigher.post5-cp310-abi3-win_amd64.whl"

• The cpXXX-abi3 tag means one wheel works across python ≥ its base (3.10+),

so py3.13 is covered even though there's no cp313-specific wheel — this is expected, not a mismatch.

• Always check the releases page for a newer tag than .post5 and newer torch

variants — the filename pattern is stable (+cu<line>torch<minor>...abi3).

• Don't build from source unless no wheel matches your torch/CUDA at all (then

you need CUDA Toolkit + MSVC; flag the cost to the user first).

Step 5 — verify (Windows)

bash
"<python>" -c "import triton; print('triton', triton.__version__)"
"<python>" -c "import sageattention; print('sageattention OK')"
"<python>" -c "import torch; print('torch still ok', torch.__version__, torch.cuda.is_available())"

All three must succeed and torch must still import with CUDA — if the third line now fails, the install clobbered torch (see Traps → roll back). Then restart ComfyUI and confirm the startup log no longer prints Could not load sageattention / triton: unavailable. Finally re-enable in the workflow: WanVideoModelLoader.attention_mode = sageattn and reconnect WanVideoTorchCompileSettings, enqueue, and confirm it samples (a torch.compile node will spend extra time on the first run compiling — that's normal).

Linux install

Official builds exist here — much simpler:

bash
# Triton: official, pip-installable; torch usually already pulls a matching triton.
pip install -U triton          # or let torch's pinned triton stand; match torch minor

# SageAttention: pip, or build from source for your GPU arch
pip install sageattention      # if a matching wheel exists for your torch/CUDA

• Use the python that runs ComfyUI (its venv/conda env) — same rule as Windows.
• Version matching still applies: torch pins a triton minor (e.g. torch 2.9.x

↔ triton 3.5.x, torch 2.10 ↔ 3.6); patch versions within a minor are interchangeable. Don't pip install triton blindly if it would upgrade past what your torch pins.

• Build deps (if building SageAttention from source): the CUDA Toolkit with

nvcc (matching your torch CUDA line), gcc/g++, and the torch headers. If CUDA is in a nonstandard path, export PATH=/usr/local/cuda-<ver>/bin:$PATH so the right nvcc is found. Building is GPU-arch specific and slow — prefer a matching prebuilt wheel when one exists.

• Verify exactly as in Windows Step 5 (import triton, import sageattention,

torch still imports with CUDA).

Mac

Triton and SageAttention are N/A on Mac — there is no CUDA. Do not attempt to install them. Use PyTorch sdpa attention (the fallback above is the permanent answer), which on Apple Silicon runs on the MPS backend. Set any attention_mode to sdpa, never load torch.compile/inductor (Triton) nodes, and run unaccelerated. If a workflow hard-requires sageattn, edit it to sdpa rather than trying to satisfy the dependency.

Verification checklist (any OS)

1. import triton succeeds and prints a version matching your torch (table above).
2. import sageattention succeeds.
3. torch STILL imports and torch.cuda.is_available() is True (the install

didn't break the env).

1. ComfyUI startup log: no Could not load sageattention, no triton: unavailable.
2. In the graph: attention_mode = sageattn loads without the No module named

'sageattention' ValueError; a torch.compile/WanVideoTorchCompileSettings node completes its (slow) first-run compile and then samples.

1. A real render completes and looks correct (SageAttention can rarely introduce

NaN/noise on some GPUs — if output degrades vs. sdpa, fall back to sdpa).

Traps

• Wrong python / global pip. Installing into system python (or the wrong

venv) means ComfyUI never imports it — the loader still crashes. Always "<that exact python>" -m pip; for Portable that's python_embeded\python.exe, for Desktop the standalone-env\python.exe. Verify with pip show sageattention run by that python.

• torch / CUDA / python wheel mismatch breaks torch. Installing a cu128 wheel

on a cu130 torch (or a torch2.9 wheel on torch2.10) can drag in mismatched CUDA DLLs and break import torch itself, or surface as a runtime DLL error. Match cu128↔12.x / cu130↔13.0 and the torch minor exactly. Pin and verify: before installing, record pip freeze | grep -i torch; after, confirm torch still imports with CUDA. If broken, roll back (pip install torch==<old>+cu<line> --index-url https://download.pytorch.org/whl/cu<line>, or uninstall the bad wheel) and re-apply the sdpa fallback.

• Stale Triton cache after a torch/GPU/driver change. Triton caches compiled

kernels in ~/.triton (%USERPROFILE%\.triton on Windows). After upgrading torch, swapping GPUs, a driver update, or a failed compile, that cache can go stale and cause torch.compile/SageAttention runs to fail even though the install is correct — recurring compile errors, RuntimeError in a Triton kernel, or a hang on the first sample. Fix: clear the cache and re-run (Triton recompiles fresh): # Windows rmdir /s /q "%USERPROFILE%\.triton" # macOS / Linux rm -rf ~/.triton Safe to delete — it's a pure cache. Do this BEFORE assuming the wheel is wrong (it's a much cheaper fix than a reinstall/roll-back). If it recurs every run, the install is genuinely mismatched (see the wheel-mismatch trap above).

• MSVC missing (Windows Triton). torch.compile/Triton errors like "Microsoft

Visual C++ ... required", cl.exe not found, or PY_SSIZE_T_CLEAN/DLL load failures usually mean no MSVC toolchain. Install Visual Studio Build Tools (C++ workload) + the latest "Visual C++ Redistributable 2015–2022"; copying msvcp140.dll/vcruntime140*.dll into the python folder is the documented last-resort fix.

• Embedded python has no headers. Portable's python_embeded lacks

include/libs, so Triton can't compile and torch.compile fails. Copy the matching python_<ver>_include_libs.zip include + libs (not lib) folders from the triton-windows releases into python_embeded\.

• py3.13 "no wheel" panic. SageAttention's Windows wheels are cp310-abi3 —

one wheel covers py3.10–3.13+. The absence of a cp313 filename is normal; do not conclude "no wheel for 3.13." (Source builds, by contrast, can genuinely lag on the newest python — another reason to use the abi3 wheel.) Triton-windows does ship py3.13-specific builds.

• CUDA line confusion. torch.version.cuda is the source of truth: 12.8 →

pick cu128 wheels, 13.0 → cu130. Don't read the system CUDA driver version — match what torch was built against.

• "Install can break torch." Treat every acceleration install as risky to the

env: get a working sdpa render first, capture the torch version, install, re-verify torch, and be ready to roll back. Never leave the user with a broken torch and no render.

• SageAttention numerical artifacts. On some GPUs (reported on H100/Hopper)

sageattn produces noise that sdpa doesn't. If a render looks worse than the sdpa version, switch that workflow back to sdpa — correctness over speed.

• First torch.compile run is slow. Inductor compiles on the first sample

(tens of seconds to minutes); that's expected, not a hang. Subsequent runs are fast. Don't "fix" it by ripping out compile unless it actually errors.

See also

• video-extend — TRAP 5 is the canonical

example: the Pusa graph ships with attention_mode=sageattn + WanVideoTorchCompileSettings; this skill is how you either satisfy or safely fall back from that. Read its TRAP 5 for the exact node-by-node sdpa fix.

• troubleshooting — "Torch / CUDA Version Errors"

and "Missing Nodes" sections for diagnosing a torch env that an install broke.

• installer-packs — packs note SageAttention/

Triton requirements in pack.yaml notes/post_install; acceleration is an opt-in post-install step, never baked into a model download.

Sources

Verified June 2026 against:

• triton-windows — github.com/woct0rdho/triton-windows (install command

pip install -U "triton-windows<3.7", the torch↔triton table, bundled CUDA toolchain, MSVC/vcredist + embedded include/libs requirements).

• SageAttention Windows wheels — github.com/woct0rdho/SageAttention/releases

tag v2.2.0-windows.post5 (the four cu128/cu130 × torch2.9.1/2.10 cp310-abi3 filenames; import name sageattention).

• WanVideoWrapper — kijai ComfyUI-WanVideoWrapper nodes: attention_mode

enum {sdpa, flash_attn_2, flash_attn_3, sageattn, sparse_sage_attention} and the No module named 'sageattention' loader crash.

• Live env — install_comfyui (action:"environment")/get_system_stats on this machine:

py3.13.12, torch 2.10.0+cu130, RTX 4090, Desktop standalone (non-embedded).

Unverified / caveats: the exact .post suffix and any newer torch variant will drift — re-check the releases page for a tag past .post5 and a wheel for your torch minor before installing. Linux pip install sageattention wheel availability depends on your torch/CUDA combo; if no wheel matches, building needs CUDA Toolkit + nvcc (flag the cost). Always confirm the chosen wheel's cu<line>/torch<minor> against the live torch.__version__/torch.version.cuda rather than trusting this doc's pinned examples.