All in-repo path references (AGENTS.md, README, old scripts, report artifacts,
test code paths) rewritten in the same commit; focused-test map extended for
.gitignore, old/scripts/*, dankclaw/comfyui/*, and report/* per this repo's
own convention ('add one before committing'). Obsidian wikilinks are
title-based and unaffected.
2.4 KiB
Lemonade and sd.cpp
Why Lemonade Server can do image generation on Strix Halo when ComfyUI cannot. Research from the Lemonade source repo (lemonade-sdk/lemonade, cloned 2026-08-14) and live verification.
The short answer
Lemonade does not run ComfyUI. Its image-generation backend is a wrapped stable-diffusion.cpp (leejet/stable-diffusion.cpp) subprocess. sd.cpp is a ggml-family native C++ runtime that ships its own HIP kernels — and those kernels include gfx1151. ComfyUI runs on PyTorch, whose standard wheels omit gfx1151. Same hardware, different runtime, different result.
From the Lemonade source
src/cpp/server/backends/sdcpp/sdcpp_server.cpp:
- Image gen is
SDServer, aWrappedServeraround a prebuilt sd.cpp binary. - Downloads
sd-<version>-bin-Linux-Ubuntu-24.04-x86_64-<backend>.zipfromleejet/stable-diffusion.cppreleases. - Backends:
cpu, cuda, metal, rocm, vulkan. - ROCm asset is
...-rocm-<version>.zip; Vulkan is...-vulkan.zip.
Backend support matrix (serverAppConfigs-docs/dev/backends-reference.md):
| Recipe | Backend | Device families |
|---|---|---|
sd-cpp |
rocm | amd_gpu (gfx103X, gfx110X, gfx1150, gfx1151, gfx1152, gfx120X) |
sd-cpp |
vulkan | amd_gpu; cpu; nvidia_gpu |
thenoise |
rocm | amd_gpu (gfx1150, gfx1151, gfx1152) — experimental |
gfx1151 is explicitly supported by sd.cpp's ROCm build. There is also a dedicated experimental thenoise ROCm backend targeting exactly the Strix Halo archs.
Engine comparison
| ComfyUI | Lemonade (sd.cpp) | |
|---|---|---|
| Runtime | PyTorch | native C++ (ggml family) |
| AMD path | needs PyTorch ROCm wheel with gfx1151 kernels — not in standard wheels | ships own HIP kernels, gfx1151 included |
| On Strix Halo | CPU only (today) | ROCm GPU, or Vulkan fallback |
| Interface | node graph web UI | server, OpenAI-style API, GUI/CLI |
This mirrors llama.cpp on the same box: ggml-family runtimes ship their own gfx1151 HIP kernels and run on ROCm; PyTorch does not.
Relevance
- If GPU image generation on Dankclaw matters, Lemonade (or bare sd.cpp) is the working path today.
- ComfyUI's node graph is the cost of switching: Lemonade is not ComfyUI.
- See ComfyUI ROCm and Vulkan for the PyTorch-side analysis showing a gfx1151-enabled torch would also make ComfyUI work.
See Also
- ComfyUI ROCm and Vulkan — the PyTorch side of this question
- ComfyUI — current CPU config
- Dankclaw Stack