iGavroche-rocm-ninodes/docs/nodes/ROCmDiffusionLoader.md

ROCmDiffusionLoader

Display name: ROCm Diffusion Loader · Category: ROCm Ninodes/Loaders

Source: rocm_nodes/core/unet_loader.py

What it does

Loads a standalone diffusion model (UNet/DiT) through ComfyUI's native comfy.sd.load_diffusion_model() and adds ROCm diagnostics. Its second job is file discovery: _get_model_files() merges ComfyUI's own diffusion_models listing with scans of the unet, unet_gguf and diffusion_models folders plus a raw os.listdir pass, so formats ComfyUI's default filter hides still appear in the dropdown. GGUF files are explicitly out of scope — use ROCmGGUFLoader.

Inputs

Name	Type	Default	Range / options	Notes
unet_name	combo (_get_model_files())	first entry	.safetensors, .ckpt, .pt, .pth, .bin, .onnx	MODEL_EXTENSIONS filters the scanned folders. Path resolution tries folders diffusion_models, unet, unet_gguf in order; raises FileNotFoundError if none resolve.
weight_dtype	combo	default	default, fp8_e4m3fn, fp8_e5m2	Applied only when not default and the filename is not fp8_scaled/fp8-scaled: then model_options["dtype"] becomes torch.float8_e4m3fn or torch.float8_e5m2. For fp8_scaled files an explicit choice is ignored (with a warning) so ComfyUI's own scale detection runs.

FUNCTION = load_unet. RETURN_TYPES = ("MODEL",).

Outputs

Name	Type	Notes
MODEL	MODEL	Result of comfy.sd.load_diffusion_model(unet_path, model_options=...); ValueError if None.

gfx1151 notes

• model_options is always passed, as {} when nothing is overridden. The code comments state this matches stock ComfyUI exactly and that omitting it produced noise-only output.
• No dtype is forced for non-fp8 models; weights keep whatever the file declares.
• Filename indicators fp8, int8, int4, quantized, bnb only trigger an informational print.
• The docstring recommends running ComfyUI with --cache-none for workflows holding several >20 GB models.
• Diagnostics print allocated/reserved memory and a fragmentation warning above 0.5 GB.

Typical wiring

ROCmDiffusionLoader.MODEL → ROCmKSampler / BasicGuider → ROCmSamplerCustomAdvanced
(+ separate VAELoader and CLIPLoader for VAE / text encoding)

Troubleshooting

• Could not find model '<name>' in any of: diffusion_models, unet, unet_gguf — the file is in a folder this node does not probe.
• A GGUF file selected here fails to parse; that is the wrong loader.
• fp8_scaled model with a non-default weight_dtype prints [WARNING] fp8_scaled models require 'default' dtype for automatic scaling and continues with auto-detection.
• OOM is caught, memory status plus a suggestion list are printed, then the error is re-raised.
• Pure noise output after changing resolution is a latent-size mismatch, not this node — see ../TROUBLESHOOTING_NOISE.md.