Multi-GPU device selection for loader nodes + CUDA context fixes (#13483)

* Fix Hunyuan 3D 2.1 multi-GPU worksplit: use cond_or_uncond instead of hardcoded chunk(2)

Amp-Thread-ID: https://ampcode.com/threads/T-019da964-2cc8-77f9-9aae-23f65da233db
Co-authored-by: Amp <amp@ampcode.com>

* Add GPU device selection to all loader nodes

- Add get_gpu_device_options() and resolve_gpu_device_option() helpers
  in model_management.py for vendor-agnostic GPU device selection
- Add device widget to CheckpointLoaderSimple, UNETLoader, VAELoader
- Expand device options in CLIPLoader, DualCLIPLoader, LTXAVTextEncoderLoader
  from [default, cpu] to include gpu:0, gpu:1, etc. on multi-GPU systems
- Wire load_diffusion_model_state_dict and load_state_dict_guess_config
  to respect model_options['load_device']
- Graceful fallback: unrecognized devices (e.g. gpu:1 on single-GPU)
  silently fall back to default

Amp-Thread-ID: https://ampcode.com/threads/T-019daa41-f394-731a-8955-4cff4f16283a
Co-authored-by: Amp <amp@ampcode.com>

* Add VALIDATE_INPUTS to skip device combo validation for workflow portability

When a workflow saved on a 2-GPU machine (with device=gpu:1) is loaded
on a 1-GPU machine, the combo validation would reject the unknown value.
VALIDATE_INPUTS with the device parameter bypasses combo validation for
that input only, allowing resolve_gpu_device_option to handle the
graceful fallback at runtime.

Amp-Thread-ID: https://ampcode.com/threads/T-019daa41-f394-731a-8955-4cff4f16283a
Co-authored-by: Amp <amp@ampcode.com>

* Set CUDA device context in outer_sample to match model load_device

Custom CUDA kernels (comfy_kitchen fp8 quantization) use
torch.cuda.current_device() for DLPack tensor export. When a model is
loaded on a non-default GPU (e.g. cuda:1), the CUDA context must match
or the kernel fails with 'Can't export tensors on a different CUDA
device index'. Save and restore the previous device around sampling.

Amp-Thread-ID: https://ampcode.com/threads/T-019daa41-f394-731a-8955-4cff4f16283a
Co-authored-by: Amp <amp@ampcode.com>

* Fix code review bugs: negative index guard, CPU offload_device, checkpoint te_model_options

- resolve_gpu_device_option: reject negative indices (gpu:-1)
- UNETLoader: set offload_device when cpu is selected
- CheckpointLoaderSimple: pass te_model_options for CLIP device,
  set offload_device for cpu, pass load_device to VAE
- load_diffusion_model_state_dict: respect offload_device from model_options
- load_state_dict_guess_config: respect offload_device, pass load_device to VAE

Amp-Thread-ID: https://ampcode.com/threads/T-019daa41-f394-731a-8955-4cff4f16283a
Co-authored-by: Amp <amp@ampcode.com>

* Fix CUDA device context for CLIP encoding and VAE encode/decode

Add torch.cuda.set_device() calls to match model's load device in:
- CLIP.encode_from_tokens: fixes 'Can't export tensors on a different
  CUDA device index' when CLIP is loaded on a non-default GPU
- CLIP.encode_from_tokens_scheduled: same fix for the hooks code path
- CLIP.generate: same fix for text generation
- VAE.decode: fixes VAE decoding on non-default GPU
- VAE.encode: fixes VAE encoding on non-default GPU

Same pattern as the existing outer_sample fix in samplers.py - saves
and restores previous CUDA device in a try/finally block.

Amp-Thread-ID: https://ampcode.com/threads/T-019dabdc-8feb-766f-b4dc-f46ef4d8ff57
Co-authored-by: Amp <amp@ampcode.com>

* Extract cuda_device_context manager, fix tiled VAE methods

Add model_management.cuda_device_context() — a context manager that
saves/restores torch.cuda.current_device when operating on a non-default
GPU. Replaces 6 copies of the manual save/set/restore boilerplate.

Refactored call sites:
- CLIP.encode_from_tokens
- CLIP.encode_from_tokens_scheduled (hooks path)
- CLIP.generate
- VAE.decode
- VAE.encode
- samplers.outer_sample

Bug fixes (newly wrapped):
- VAE.decode_tiled: was missing device context entirely, would fail
  on non-default GPU when called from 'VAE Decode (Tiled)' node
- VAE.encode_tiled: same issue for 'VAE Encode (Tiled)' node

Amp-Thread-ID: https://ampcode.com/threads/T-019dabdc-8feb-766f-b4dc-f46ef4d8ff57
Co-authored-by: Amp <amp@ampcode.com>

* Restore CheckpointLoaderSimple, add CheckpointLoaderDevice

Revert CheckpointLoaderSimple to its original form (no device input)
so it remains the simple default loader.

Add new CheckpointLoaderDevice node (advanced/loaders) with separate
model_device, clip_device, and vae_device inputs for per-component
GPU placement in multi-GPU setups.

Amp-Thread-ID: https://ampcode.com/threads/T-019dabdc-8feb-766f-b4dc-f46ef4d8ff57
Co-authored-by: Amp <amp@ampcode.com>

---------

Co-authored-by: Amp <amp@ampcode.com>
This commit is contained in:
Jedrzej Kosinski
2026-04-23 19:10:33 -07:00
committed by GitHub
parent 7b8b3673ff
commit aa464b36b3
5 changed files with 371 additions and 178 deletions

127
nodes.py
View File

@@ -608,6 +608,73 @@ class CheckpointLoaderSimple:
out = comfy.sd.load_checkpoint_guess_config(ckpt_path, output_vae=True, output_clip=True, embedding_directory=folder_paths.get_folder_paths("embeddings"))
return out[:3]
class CheckpointLoaderDevice:
@classmethod
def INPUT_TYPES(s):
device_options = comfy.model_management.get_gpu_device_options()
return {
"required": {
"ckpt_name": (folder_paths.get_filename_list("checkpoints"), {"tooltip": "The name of the checkpoint (model) to load."}),
},
"optional": {
"model_device": (device_options, {"advanced": True, "tooltip": "Device for the diffusion model (UNET)."}),
"clip_device": (device_options, {"advanced": True, "tooltip": "Device for the CLIP text encoder."}),
"vae_device": (device_options, {"advanced": True, "tooltip": "Device for the VAE."}),
}
}
RETURN_TYPES = ("MODEL", "CLIP", "VAE")
OUTPUT_TOOLTIPS = ("The model used for denoising latents.",
"The CLIP model used for encoding text prompts.",
"The VAE model used for encoding and decoding images to and from latent space.")
FUNCTION = "load_checkpoint"
CATEGORY = "advanced/loaders"
DESCRIPTION = "Loads a diffusion model checkpoint with per-component device selection for multi-GPU setups."
@classmethod
def VALIDATE_INPUTS(cls, model_device="default", clip_device="default", vae_device="default"):
return True
def load_checkpoint(self, ckpt_name, model_device="default", clip_device="default", vae_device="default"):
ckpt_path = folder_paths.get_full_path_or_raise("checkpoints", ckpt_name)
model_options = {}
resolved_model = comfy.model_management.resolve_gpu_device_option(model_device)
if resolved_model is not None:
if resolved_model.type == "cpu":
model_options["load_device"] = model_options["offload_device"] = resolved_model
else:
model_options["load_device"] = resolved_model
te_model_options = {}
resolved_clip = comfy.model_management.resolve_gpu_device_option(clip_device)
if resolved_clip is not None:
if resolved_clip.type == "cpu":
te_model_options["load_device"] = te_model_options["offload_device"] = resolved_clip
else:
te_model_options["load_device"] = resolved_clip
# VAE device is passed via model_options["load_device"] which
# load_state_dict_guess_config forwards to the VAE constructor.
# If vae_device differs from model_device, we override after loading.
resolved_vae = comfy.model_management.resolve_gpu_device_option(vae_device)
out = comfy.sd.load_checkpoint_guess_config(ckpt_path, output_vae=True, output_clip=True, embedding_directory=folder_paths.get_folder_paths("embeddings"), model_options=model_options, te_model_options=te_model_options)
model_patcher, clip, vae = out[:3]
# Apply VAE device override if it differs from the model device
if resolved_vae is not None and vae is not None:
vae.device = resolved_vae
if resolved_vae.type == "cpu":
offload = resolved_vae
else:
offload = comfy.model_management.vae_offload_device()
vae.patcher.load_device = resolved_vae
vae.patcher.offload_device = offload
return (model_patcher, clip, vae)
class DiffusersLoader:
SEARCH_ALIASES = ["load diffusers model"]
@@ -807,14 +874,21 @@ class VAELoader:
@classmethod
def INPUT_TYPES(s):
return {"required": { "vae_name": (s.vae_list(s), )}}
return {"required": { "vae_name": (s.vae_list(s), )},
"optional": {
"device": (comfy.model_management.get_gpu_device_options(), {"advanced": True}),
}}
RETURN_TYPES = ("VAE",)
FUNCTION = "load_vae"
CATEGORY = "loaders"
@classmethod
def VALIDATE_INPUTS(cls, device="default"):
return True
#TODO: scale factor?
def load_vae(self, vae_name):
def load_vae(self, vae_name, device="default"):
metadata = None
if vae_name == "pixel_space":
sd = {}
@@ -827,7 +901,8 @@ class VAELoader:
else:
vae_path = folder_paths.get_full_path_or_raise("vae", vae_name)
sd, metadata = comfy.utils.load_torch_file(vae_path, return_metadata=True)
vae = comfy.sd.VAE(sd=sd, metadata=metadata)
resolved = comfy.model_management.resolve_gpu_device_option(device)
vae = comfy.sd.VAE(sd=sd, metadata=metadata, device=resolved)
vae.throw_exception_if_invalid()
return (vae,)
@@ -953,13 +1028,20 @@ class UNETLoader:
def INPUT_TYPES(s):
return {"required": { "unet_name": (folder_paths.get_filename_list("diffusion_models"), ),
"weight_dtype": (["default", "fp8_e4m3fn", "fp8_e4m3fn_fast", "fp8_e5m2"], {"advanced": True})
},
"optional": {
"device": (comfy.model_management.get_gpu_device_options(), {"advanced": True}),
}}
RETURN_TYPES = ("MODEL",)
FUNCTION = "load_unet"
CATEGORY = "advanced/loaders"
def load_unet(self, unet_name, weight_dtype):
@classmethod
def VALIDATE_INPUTS(cls, device="default"):
return True
def load_unet(self, unet_name, weight_dtype, device="default"):
model_options = {}
if weight_dtype == "fp8_e4m3fn":
model_options["dtype"] = torch.float8_e4m3fn
@@ -969,6 +1051,13 @@ class UNETLoader:
elif weight_dtype == "fp8_e5m2":
model_options["dtype"] = torch.float8_e5m2
resolved = comfy.model_management.resolve_gpu_device_option(device)
if resolved is not None:
if resolved.type == "cpu":
model_options["load_device"] = model_options["offload_device"] = resolved
else:
model_options["load_device"] = resolved
unet_path = folder_paths.get_full_path_or_raise("diffusion_models", unet_name)
model = comfy.sd.load_diffusion_model(unet_path, model_options=model_options)
return (model,)
@@ -980,7 +1069,7 @@ class CLIPLoader:
"type": (["stable_diffusion", "stable_cascade", "sd3", "stable_audio", "mochi", "ltxv", "pixart", "cosmos", "lumina2", "wan", "hidream", "chroma", "ace", "omnigen2", "qwen_image", "hunyuan_image", "flux2", "ovis", "longcat_image"], ),
},
"optional": {
"device": (["default", "cpu"], {"advanced": True}),
"device": (comfy.model_management.get_gpu_device_options(), {"advanced": True}),
}}
RETURN_TYPES = ("CLIP",)
FUNCTION = "load_clip"
@@ -989,12 +1078,20 @@ class CLIPLoader:
DESCRIPTION = "[Recipes]\n\nstable_diffusion: clip-l\nstable_cascade: clip-g\nsd3: t5 xxl/ clip-g / clip-l\nstable_audio: t5 base\nmochi: t5 xxl\ncosmos: old t5 xxl\nlumina2: gemma 2 2B\nwan: umt5 xxl\n hidream: llama-3.1 (Recommend) or t5\nomnigen2: qwen vl 2.5 3B"
@classmethod
def VALIDATE_INPUTS(cls, device="default"):
return True
def load_clip(self, clip_name, type="stable_diffusion", device="default"):
clip_type = getattr(comfy.sd.CLIPType, type.upper(), comfy.sd.CLIPType.STABLE_DIFFUSION)
model_options = {}
if device == "cpu":
model_options["load_device"] = model_options["offload_device"] = torch.device("cpu")
resolved = comfy.model_management.resolve_gpu_device_option(device)
if resolved is not None:
if resolved.type == "cpu":
model_options["load_device"] = model_options["offload_device"] = resolved
else:
model_options["load_device"] = resolved
clip_path = folder_paths.get_full_path_or_raise("text_encoders", clip_name)
clip = comfy.sd.load_clip(ckpt_paths=[clip_path], embedding_directory=folder_paths.get_folder_paths("embeddings"), clip_type=clip_type, model_options=model_options)
@@ -1008,7 +1105,7 @@ class DualCLIPLoader:
"type": (["sdxl", "sd3", "flux", "hunyuan_video", "hidream", "hunyuan_image", "hunyuan_video_15", "kandinsky5", "kandinsky5_image", "ltxv", "newbie", "ace"], ),
},
"optional": {
"device": (["default", "cpu"], {"advanced": True}),
"device": (comfy.model_management.get_gpu_device_options(), {"advanced": True}),
}}
RETURN_TYPES = ("CLIP",)
FUNCTION = "load_clip"
@@ -1017,6 +1114,10 @@ class DualCLIPLoader:
DESCRIPTION = "[Recipes]\n\nsdxl: clip-l, clip-g\nsd3: clip-l, clip-g / clip-l, t5 / clip-g, t5\nflux: clip-l, t5\nhidream: at least one of t5 or llama, recommended t5 and llama\nhunyuan_image: qwen2.5vl 7b and byt5 small\nnewbie: gemma-3-4b-it, jina clip v2"
@classmethod
def VALIDATE_INPUTS(cls, device="default"):
return True
def load_clip(self, clip_name1, clip_name2, type, device="default"):
clip_type = getattr(comfy.sd.CLIPType, type.upper(), comfy.sd.CLIPType.STABLE_DIFFUSION)
@@ -1024,8 +1125,12 @@ class DualCLIPLoader:
clip_path2 = folder_paths.get_full_path_or_raise("text_encoders", clip_name2)
model_options = {}
if device == "cpu":
model_options["load_device"] = model_options["offload_device"] = torch.device("cpu")
resolved = comfy.model_management.resolve_gpu_device_option(device)
if resolved is not None:
if resolved.type == "cpu":
model_options["load_device"] = model_options["offload_device"] = resolved
else:
model_options["load_device"] = resolved
clip = comfy.sd.load_clip(ckpt_paths=[clip_path1, clip_path2], embedding_directory=folder_paths.get_folder_paths("embeddings"), clip_type=clip_type, model_options=model_options)
return (clip,)
@@ -2098,6 +2203,7 @@ NODE_CLASS_MAPPINGS = {
"InpaintModelConditioning": InpaintModelConditioning,
"CheckpointLoader": CheckpointLoader,
"CheckpointLoaderDevice": CheckpointLoaderDevice,
"DiffusersLoader": DiffusersLoader,
"LoadLatent": LoadLatent,
@@ -2115,6 +2221,7 @@ NODE_DISPLAY_NAME_MAPPINGS = {
# Loaders
"CheckpointLoader": "Load Checkpoint With Config (DEPRECATED)",
"CheckpointLoaderSimple": "Load Checkpoint",
"CheckpointLoaderDevice": "Load Checkpoint (Device)",
"VAELoader": "Load VAE",
"LoraLoader": "Load LoRA (Model and CLIP)",
"LoraLoaderModelOnly": "Load LoRA",